View source for Middlesex County, Massachusetts

{{short description|County in Massachusetts, United States}}
{{Use American English|date=June 2025}}
{{Use mdy dates|date=April 2024}}
{{Infobox U.S. county
 | county               = Middlesex County
 | state                = Massachusetts
 | type                 = [[List of counties in Massachusetts|County]]
 | seal                 = Middlesex County Seal.png
 | founded year         = 1643
 | founded date         = May 10
 | seat                 = [[Lowell, Massachusetts|Lowell]] and [[Cambridge, Massachusetts|Cambridge]] ([[de jure]])
 | largest city         = [[Cambridge, Massachusetts|Cambridge]]
 | coordinates          = {{coord|42.49|-71.39|display=title,inline|type:adm2nd_region:US-MA_source:UScensus1990}}
 | area_total_sq_mi     = 847
 | area_land_sq_mi      = 818
 | area_water_sq_mi     = 29
 | area percentage      = 3.5
 | census yr            = 2020
 | pop                = 1632002
 | pop_est_as_of        = 2024
 | population_est     = 1668956
 {{gain}}
 | density_sq_mi        = auto
 | time zone          = Eastern
 | web                  = 
 | district             = 3rd
 | district2            = 4th
 | district3            = 5th
 | district4            = 6th
 | district5            = 7th
 | ex image           = {{multiple image
  | total_width              = 288
  | border                   = infobox
  | perrow                   = 1/2/2/2
  | caption_align            = center
  | image1                   = Harvard_yard_winter_2009j.JPG
  | alt1                     = HY
  | caption1                 = [[Harvard University]]
  | image2                   = Front_of_boott_mill.jpg
  | alt2                     = LM
  | caption2                 = [[Lowell Mills]]
  | image3                   = Walden Pond, 2010.jpg
  | alt3                     = WP
  | caption3                 = [[Walden Pond]]
  | image4                   = Eaton_Hall,_Tufts.jpg
  | alt4                     = TU
  | caption4                 = [[Tufts University]]
  | image5                   = Hartwell_Tavern_2.jpeg
  | alt5                     = HT
  | caption5                 = [[Hartwell Tavern]]
  | image6                   = Great_Dome,_Massachusetts_Institute_of_Technology,_Aug_2019.jpg
  | alt6                     = MIT
  | caption6                 = [[MIT]]
 
}}

 | named for            = [[Middlesex]], [[Kingdom of England|England]] 
}}

'''Middlesex County''' is a county located in the [[Commonwealth (U.S. state)|Commonwealth]] of [[Massachusetts]], United States. As of the [[2020 United States census|2020 census]], the [[population]] was 1,632,002,<ref>{{cite web|url=https://data.census.gov/cedsci/profile?g=0500000US25017|title=Census - Geography Profile: Middlesex County, Massachusetts|publisher=[[United States Census Bureau]]|access-date=November 14, 2021|archive-date=November 15, 2021|archive-url=https://web.archive.org/web/20211115032626/https://data.census.gov/cedsci/profile?g=0500000US25017|url-status=live}}</ref> making it the most populous county in both Massachusetts and [[New England]] and the [[List of the most populous counties in the United States|20th most populous county in the United States]]. This makes the county the most populous county on the East Coast outside of New York or Florida. Middlesex County is one of two U.S. counties (along with [[Santa Clara County, California]]) to be amongst the top 25 counties with the highest household income and the 25 most populated counties. It is included in the Census Bureau's [[Boston]]–[[Cambridge, Massachusetts|Cambridge]]–[[Newton, Massachusetts|Newton]], MA–[[New Hampshire|NH]] [[Greater Boston|Metropolitan Statistical Area]]. As part of the [[2020 United States census]], the Commonwealth's mean [[center of population]] for that year was [[Geographic coordinate system|geo-centered]] in Middlesex County, in the town of [[Natick, Massachusetts|Natick]]<ref>{{Cite web |date=April 1, 2020 |title=STATEFP,STNAME,POPULATION,LATITUDE,LONGITUDE |url=https://www2.census.gov/geo/docs/reference/cenpop2020/CenPop2020_Mean_ST.txt |access-date=October 20, 2022 |website=[[United States Census Bureau]] |archive-date=April 1, 2022 |archive-url=https://web.archive.org/web/20220401024320/https://www2.census.gov/geo/docs/reference/cenpop2020/CenPop2020_Mean_ST.txt |url-status=live }}</ref>{{Efn|That center was at ''{{coord|42.273659|-71.350366}}''.}} (this is not to be confused with the [[geographic center]] of Massachusetts, which is in [[Rutland, Massachusetts|Rutland]], [[Worcester County, Massachusetts|Worcester County]]).

On July 11, 1997, Massachusetts abolished the executive government of Middlesex County primarily due to the county's [[insolvency]].<ref>{{Cite journal|url=https://vc.bridgew.edu/cgi/viewcontent.cgi?article=1279&context=undergrad_rev|first=Brendan|last=Concannon|journal=Undergraduate Review|access-date=July 31, 2023|date=2014|title=Massachusetts County Government: A Viable Institution?|volume=10|pages=55–62|publisher=Bridgewater State University}}</ref> Middlesex County continues to exist as a geographic boundary<ref name="MGL34B">{{MassGenLaws|34B}}</ref> and is used primarily as district jurisdictions within the court system and for other administrative purposes; for example, as an [[election]] district. The [[National Weather Service]] weather alerts (such as [[severe thunderstorm warning]]) continue to localize based on Massachusetts's counties.

==History==
The county was created by the [[Massachusetts General Court]] on May 10, 1643, when it was ordered that "the whole [[Massachusetts Bay Colony|plantation]] within this jurisdiction be divided into four [[Shire|shires.]]" Middlesex initially contained [[Charlestown, Boston|Charlestown]], [[Cambridge, Massachusetts|Cambridge]], [[Watertown, Massachusetts|Watertown]], [[Sudbury, Massachusetts|Sudbury]], [[Concord, Massachusetts|Concord]], [[Woburn, Massachusetts|Woburn]], [[Medford, Massachusetts|Medford]], and [[Reading, Massachusetts|Reading]].<ref name="Boston Annex">Davis, William T. ''Bench and Bar of the Commonwealth of Massachusetts'', p. 44. The Boston History Company, 1895.</ref> In 1649 the first Middlesex County Registry of Deeds was created in Cambridge.

On April 19, 1775, Middlesex was the site of the first armed conflict of the [[American Revolutionary War]].

In 1855, the Massachusetts State Legislature created a minor Registry of Deeds for the Northern District of Middlesex County in Lowell.<ref name="Boston Annex" />

In the late 19th century and early 20th century, [[Boston]] annexed several of its adjacent cities and towns including Charlestown and [[Brighton, Boston|Brighton]] from Middlesex County, resulting in an enlargement and accretion toward [[Suffolk County, Massachusetts|Suffolk County]].<ref name="Boston Annex" />

Beginning prior to the dissolution of the executive county government, the county comprised two regions with separate county seats for administrative purposes:
*The Middlesex-North District (smaller) with its [[county seat]] in [[Lowell, Massachusetts|Lowell]] under the Registry of Deeds consisted of the city of Lowell, and its adjacent towns of [[Billerica, Massachusetts|Billerica]], [[Carlisle, Massachusetts|Carlisle]], [[Chelmsford, Massachusetts|Chelmsford]], [[Dracut, Massachusetts|Dracut]], [[Dunstable, Massachusetts|Dunstable]], [[Tewksbury, Massachusetts|Tewksbury]], [[Tyngsborough, Massachusetts|Tyngsborough]], [[Westford, Massachusetts|Westford]] and [[Wilmington, Massachusetts|Wilmington]].
*The Middlesex-South District (larger) with the county seat in [[Cambridge, Massachusetts|Cambridge]]<ref name="GR6">{{cite web|url=http://www.naco.org/Counties/Pages/FindACounty.aspx |access-date=June 7, 2011 |title=Find a County |publisher=National Association of Counties |url-status=dead |archive-url=https://web.archive.org/web/20110531210815/http://www.naco.org/Counties/Pages/FindACounty.aspx |archive-date=May 31, 2011 }}</ref> consisted of the remaining 44 cities and towns of Middlesex County.<ref name="MGL36-1">{{M.G.L.|36|1}}</ref>

Since the start of the 21st century, much of the current and former county offices have physically decentralized from the Cambridge seat, with the sole exceptions being the Registry of Deeds and the Middlesex Probate and Family Court, which both retain locations in Cambridge and Lowell. Since the first quarter of 2008, the Superior Courthouse<ref name="Superior court move" /><ref>{{cite news |last1=Redmond |first1=Lisa |date=March 10, 2008 |title=Middlesex Superior Court moving to Woburn |url=http://www.lowellsun.com/breakingnews/ci_8521720 |publisher=Digital First Media |agency=[[Lowell Sun]] |access-date=January 31, 2018 |quote=WOBURN &ndash; Middlesex Superior Court, currently located in the Edward J. Sullivan Courthouse in Cambridge, will move to a new facility in Woburn in the TradeCenter on Sylvan Road beginning Friday, according to Chief Justice for Administration and Management Robert A. Mulligan. |archive-date=January 29, 2018 |archive-url=https://web.archive.org/web/20180129141612/http://www.lowellsun.com/breakingnews/ci_8521720 |url-status=live }}</ref> has been seated in the city of [[Woburn, Massachusetts|Woburn]];<ref>{{cite web |url=https://www.tradecenter128.com/media.htm |title=Press Release: Middlesex Superior Court Moves to Woburn |date=March 17, 2008 |publisher=Cummings Properties, LLC |access-date=January 31, 2018 |quote=Woburn, MA, March 17, 2008 &ndash; The new furniture has been installed, years of case files have been dusted off, moved and organized, and the computers are all hooked up and ready to go. After 40 years in Cambridge, the Superior Court is open and ready for business in Woburn. [ ... ] Serving nearly all of the 54 communities in Middlesex County, the new Woburn building houses 15 courtrooms, clerks' offices, judges' chambers, the probation department, the law library, and more. In addition, the Court estimates that more than 400 people will use the building every day, including, lawyers, judges, administrative staff, jurors, plaintiffs, defendants, visitors, and others who work at the building and use the system. |archive-date=January 30, 2018 |archive-url=https://web.archive.org/web/20180130091238/https://www.tradecenter128.com/media.htm |url-status=live }}</ref><ref>{{cite news |last1=Properties |first1=Cummings |date=September 20, 2013 |title=Press Release:Middlesex Superior Court renews lease in Woburn |url=https://patch.com/massachusetts/woburn/middlesex-superior-court-renews-lease-in-woburn |work=Cummings Properties, Business |publisher=Patch Media |access-date=January 31, 2018 |quote=The Commonwealth of Massachusetts has extended its lease for the Middlesex County Superior Courthouse at TradeCenter 128 in Woburn for a seven-year term. This renewal comes five years after the Court moved from the Edward J. Sullivan Courthouse in Cambridge, which was in need of extensive renovations and has since been slated for redevelopment. |archive-date=January 29, 2018 |archive-url=https://web.archive.org/web/20180129141451/https://patch.com/massachusetts/woburn/middlesex-superior-court-renews-lease-in-woburn |url-status=live }}</ref> the Sheriff's Office is now administratively seated in the city of [[Medford, Massachusetts|Medford]] and the Cambridge-based County Jail<ref>{{cite news |last1=Hanson |first1=Melissa |date=June 28, 2014 |title=Middlesex Jail in Cambridge closes |url=https://www.bostonglobe.com/metro/2014/06/28/middlesex-jail-cambridge-closes/tH9JuyPXowVZTQLGQ9VdkJ/story.html |url-status=dead|newspaper=The Boston Globe |archive-url=https://web.archive.org/web/20180129141409/https://www.bostonglobe.com/metro/2014/06/28/middlesex-jail-cambridge-closes/tH9JuyPXowVZTQLGQ9VdkJ/story.html|archive-date=January 29, 2018|access-date=February 10, 2018 |url-access=subscription |quote=The Middlesex Jail at the Edward J. Sullivan Courthouse in Cambridge closed Saturday after 32 years of operation, according to Middlesex Sheriff Peter J. Koutoujian.}}</ref> has since been amalgamated with another county jail facility in Billerica.<ref>{{cite news |last1=Boeri |first1=David |date=June 30, 2014 |title=One Last Elevator Ride Down: Cambridge High-Rise Jail Is No More |url=http://www.wbur.org/news/2014/06/30/middlesex-jail-cambridge-billerica |work=[[WBUR]] |access-date=February 10, 2018 |quote=A high-security weekend operation has emptied the Middlesex County Jail in Cambridge of all its inmates. |archive-date=January 29, 2018 |archive-url=https://web.archive.org/web/20180129200901/http://www.wbur.org/news/2014/06/30/middlesex-jail-cambridge-billerica |url-status=live }}</ref>  The Cambridge District Court (which has jurisdiction for Arlington, Belmont and Cambridge); along with the Middlesex County District Attorney's Office, although not a part of the Middlesex County government, was also relatedly forced to relocate to Medford at the time of the closure of the Superior Courthouse building in Cambridge.<ref>{{cite news |last1=Barry |first1=Rob |date=February 26, 2009 |title=Cambridge Court opens in Medford |url=http://www.wickedlocal.com/article/20090226/news/302269714 |publisher=WickedLocal |agency=[[GateHouse Media|GateHouse Media, LLC]] |access-date=February 10, 2018 |url-access=subscription |quote=The Cambridge District Court moved into Medford this week, placing itself in the former Cross Country building at 4040 Mystic Valley Pkwy. |archive-date=January 29, 2018 |archive-url=https://web.archive.org/web/20180129141718/http://www.wickedlocal.com/article/20090226/news/302269714 |url-status=live }}</ref><ref>{{cite news |last1=Kenney |first1=Joan |last2=Whiting |first2=Charlotte |date=February 17, 2009 |title=Third District Court of Middlesex County Relocates From Cambridge to Medford |url=http://www.bostonbar.org/pub/bw/0809/022309/court_move.pdf |department=Public Information Office |work=Massachusetts Supreme Judicial Court |publisher=[[Boston Bar Association]] |access-date=February 10, 2018 |quote=Chief Justice for Administration and Management Robert A. Mulligan today announced that the Third District Court of Middlesex County, currently located in the Edward J. Sullivan Courthouse in Cambridge, will move to a new court facility on the Mystic Valley Parkway in Medford after the close of business on February 20, 2009, and open for business at this new site on Monday, February 23, 2009. |archive-date=January 29, 2018 |archive-url=https://web.archive.org/web/20180129195027/http://www.bostonbar.org/pub/bw/0809/022309/court_move.pdf |url-status=live }}</ref>

== Government and politics ==
Of the fourteen counties of Massachusetts, Middlesex is one of eight<ref>{{cite web |url=https://malegislature.gov/Laws/GeneralLaws/PartI/TitleVI/Chapter34B |title=General Laws of Massachusetts, Chapter 34B. Abolition of County Government |work=Massachusetts General Court |access-date=November 26, 2016 |archive-date=May 25, 2021 |archive-url=https://web.archive.org/web/20210525142932/https://malegislature.gov/Laws/GeneralLaws/PartI/TitleVI/Chapter34b |url-status=live }}</ref> which have had no county government or county commissioners since July 1, 1998, when county functions were assumed by state agencies at local option following a change in state law.<ref name="MGL34B"/> Immediately prior to its dissolution, the executive branch consisted of three [[County Commissioner]]s elected at-large to staggered four-year terms. There was a County Treasurer elected to a six-year term. The county derived its revenue primarily from document filing fees at the Registries of Deeds and from a Deeds Excise Tax; also a transfer tax was assessed on the sale price of real estate and collected by the Registries of Deeds.<ref>Middlesex County Directory: 1993-1995, (Cambridge: Middlesex County Commissioners Office, 1995)</ref>

Budgets as proposed by the County Commissioners were approved by a County Advisory Board that consisted of a single representative of each of the 54 cities and towns in Middlesex County. The votes of the individual members of the advisory board were weighted based on the overall valuation of property in their respective communities.

The [[Middlesex County Sheriff's Office|County Sheriff]] and two Registers of Deeds (one for the Northern District at Lowell and another for the Southern District at Cambridge) are each elected to serve six-year terms.<ref name="MGL34-4">{{MassGenLaws|34|4}}</ref> Besides the employees of the Sheriff's Office and the two Registries of Deeds, the county had a Maintenance Department, a Security Department, some administrative staff in the Treasurer's and Commissioners' Offices, and the employees of the hospital.

The county government also owned and operated the [[Massachusetts Superior Court|Superior Courthouse]], one of which was formerly in Cambridge (since 2008 relocated to Woburn.)<ref name="Superior court move">{{cite news |last1=Moskowitz |first1=Eric |date=February 14, 2008 |title=Court move a hassle for commuters |url=http://archive.boston.com/news/local/articles/2008/02/14/court_move_a_hassle_for_commuters/ |access-date=January 29, 2018 |archive-date=November 5, 2016 |archive-url=https://web.archive.org/web/20161105032846/http://archive.boston.com/news/local/articles/2008/02/14/court_move_a_hassle_for_commuters/ |url-status=live }}</ref> and one in Lowell; and the defunct [[Middlesex County Hospital]] in the city of Waltham.

The legislation abolishing the Middlesex County executive retained the Sheriff and Registers of Deeds as independently elected officials, and transferred the Sheriff's Office under the state Department of Public Safety and the two Registry of Deeds offices to the Massachusetts Secretary of State's Office.<ref name="MGL34B-10">{{MassGenLaws|34B|10}}</ref> Additionally, all county maintenance and security employees were absorbed into the corresponding staffs of the [[Judiciary of Massachusetts#Trial Court|Massachusetts Trial Court]]. The legislation also transferred ownership of the two Superior Courthouses to the Commonwealth of Massachusetts. The hospital was closed. Finally, the office of County Commissioner was immediately abolished and the office of County Treasurer was abolished as of December 31, 2002.<ref name="MGL34B-2">{{MassGenLaws|34B|2}}</ref> Any county roads transferred to the Commonwealth as part of the dissolution. The other administrative duties (such as Sheriff, Department of Deeds and [[Courts of Massachusetts|court system]], etc.) and all supporting staff were transferred under the Commonwealth as well.

{| class="wikitable collapsible collapsed"
! colspan="2" | District attorneys of Middlesex County<ref>{{cite book |last1=Conklin |first1=Edwin P. |title=Middlesex County and Its People |date=1927 |publisher=Lewis Historical Publishing Company |location=New York |page=119 |url=https://books.google.com/books?id=hoElAQAAMAAJ |access-date=August 6, 2023}}</ref>
|-
! District attorney !! Term
|-
|[[Samuel Dana (Massachusetts politician)|Samuel Dana]]
|1807–1811
|-
|[[Timothy Fuller]]
|1811–1812
|-
|[[Asahel Stearns]]
|1813–1832
|-
|[[Asahel Huntington]]
|1832–1845
|-
|[[Albert H. Nelson]]
|1845–1848
|-
|[[Charles R. Train]]
|1848–1851
|-
|[[Asa W. Farr]]
|1851–1853
|-
|[[Charles R. Train]]
|1853–1855
|-
|[[Isaac S. Morse]]
|1855–1872
|-
|[[John B. Goodrich]]
|1872–1874
|-
|[[George Stevens (Massachusetts politician)|George Stevens]]
|1874–1879
|-
|[[John Wilkes Hammond]]
|1879–1880
|-
|[[William Burnham Stevens]]
|1880–1890
|-
|[[Patrick H. Cooney]]
|1890–1893
|-
|[[Fred N. Wier]]
|1893–1902
|-
|[[George A. Sanderson (judge)|George A. Sanderson]]
|1902–1907
|-
|[[Hugh Bancroft (attorney)|Hugh Bancroft]]
|1907–1908
|-
|[[John J. Higgins]]
|1908–1913
|-
|[[William J. Corcoran (attorney)|William J. Corcoran]]
|1913–1917
|-
|[[Nathan A. Tufts]]
|1917–1921
|-
|[[Endicott Peabody Saltonstall]]
|1921–1922
|-
|[[Arthur Kenneth Reading]]
|1922–1927
|-
|[[Robert T. Bushnell]]
|1927–1931
|-
|[[Warren L. Bishop]]
|1931–1938
|-
|[[William G. Andrew]]
|1938–1939
|-
|[[Robert F. Bradford]]
|1939–1945
|-
|[[George E. Thompson]]
|1945–1956
|-
|[[Ephraim Martin]]
|1956–1957
|-
|[[James O'Dea Jr.]]
|1957–1959
|-
|[[John J. Droney]]
|1959–1983
|-
|[[Scott Harshbarger]]
|1983–1991
|-
|[[Thomas Reilly (Massachusetts politician)|Thomas Reilly]]
|1991–1999
|-
|[[Martha Coakley]]
|1999–2007
|-
|[[Gerard Leone]]
|2007–2013
|-
|[[Marian T. Ryan]]
|2013–present
|}

{| class="wikitable collapsible collapsed"
! colspan="2" | Sheriffs of Middlesex County<ref name="Edward M. Burns, Esq">{{Cite web|url=http://www.middlesexsheriff.org/about_history.htm|title=History of Middlesex Sheriff's Office|author=Edward M. Burns, Esq.|work=Middlesex Special Sheriff|date=October 20, 2009|archiveurl=https://web.archive.org/web/20091213215053/http://www.middlesexsheriff.org/about_history.htm|archivedate=December 13, 2009|url-status=dead}}</ref>
|-
! Sheriff !! Term
|-
| Capt. [[Timothy Phillips (Massachusetts politician)|Timothy Phillips]]
| 1692–1702
|-
| Capt. Samuel Gookin
| 1702–1714
|-
| Col. Edmund Goffe
| 1714–1717
|-
| Samuel Gookin<sup>(2nd term)</sup>
| 1717–1729
|-
| Daniel Foster
| 1729–1731
|-
| Richard Foster, Jr.
| 1731–1764
|-
| Col. David Phips
| 1764–1775
|-
| Col. James Prescott
| 1775–1781
|-
| Col. [[Loammi Baldwin]]
| 1781–1794
|-
| Maj. [[Joseph Hosmer (Massachusetts politician)|Joseph Hosmer]]
| 1794–1808
|-
| Gen. William Hildreth, Jr.
| 1808–1813
|-
| Gen. Nathaniel Austin, Jr.
| 1813–1831
|-
| Benjamin Franklin Varnum
| 1831–1841
|-
| Col. Samuel Chandler
| 1841–1851
|-
| Fisher Ames Hildreth
| 1851–1853
|-
| John Sheppard Keyes
| 1853–1859
|-
| Charles Kimball
| 1859–1879
|-
| Eben Winslow Fiske
| 1879–1883
|-
| Henry Greenwood Cushing
| 1883–1899
|-
| John Robert Fairbain
| 1899–1934
|-
| Joseph M. McElroy
| 1934–1947
|-
| Loring R. Kew
| 1947-1947
|-
| Louis E. Boutwell
| 1948–1949
|-
| Howard W. Fitzpatrick
| 1949–1970
|-
| [[John J. Buckley (sheriff)|John J. Buckley]]
| 1970–1980
|-
| [[Edward Henneberry]]
| 1980–1984
|-
| William Quealy ''(acting)''
| 1984–1985
|-
| [[John P. McGonigle]]
| 1985–1994
|-
| Robert C. Krekorian ''(acting)''
| 1994
|-
|-
| Anthony M. Sasso ''(acting)''
| 1994
|-
| R. Bradford Bailey
| 1994–1996
|-
| [[James DiPaola]]
| 1996–2010
|-
| [[John Granara]] ''(Special)''
| 2010–2011
|-
| [[Peter Koutoujian]]  
| 2011–Present
|}

===Administrative structure today===
Records of land ownership in Middlesex County continue to be maintained at the two Registries of Deeds. Besides the Sheriff and the two Registers of Deeds, the Middlesex District Attorney, the Middlesex Register of Probate and the Middlesex Clerk of Courts (which were already part of state government before the abolition of Middlesex County government) are all elected countywide to six-year terms.

In Middlesex County (as in the entirety of the Commonwealth of Massachusetts), the governmental functions such as property tax assessment and collection, public education, road repair and maintenance, and elections were all conducted at the municipal city and town level and not by the county government.

In 2012 the 22-story Superior Court Building in Cambridge which was transferred from the abolished Executive County government was sold<ref>{{Cite news |last=Baldassari |first=Erin |date=December 17, 2012 |title=Leggat McCall wins bid for Sullivan Courthouse redevelopment in Cambridge |publisher=WickedLocal |agency=[[GateHouse Media|GateHouse Media, LLC]] |url=http://cambridge.wickedlocal.com/x1107423193/Leggat-McCall-wins-bid-for-Sullivan-Courthouse-redevelopment-in-Cambridge |url-access=subscription |access-date=December 17, 2012 |quote=Leggat McCall Properties was selected from a pool of seven bidders to redevelop the 22-story, 600,000-square-foot EJ Sullivan Courthouse in East Cambridge, the state announced Friday, Dec. 14. |archive-date=January 30, 2018 |archive-url=https://web.archive.org/web/20180130014120/http://cambridge.wickedlocal.com/x1107423193/Leggat-McCall-wins-bid-for-Sullivan-Courthouse-redevelopment-in-Cambridge |url-status=live }}</ref><ref>{{Cite news |last=Parker |first=Brock |date=November 16, 2011 |title=State advertising 22-story Sullivan Courthouse, seeking to sell by September |publisher=[[Boston.com|Boston Globe Media Partners, LLC]] |url=http://archive.boston.com/yourtown/news/cambridge/2011/11/state_advertising_22-story_sul.html |url-access=subscription |access-date=February 10, 2018 |quote=State officials are advertising for a buyer for the 22-story, asbestos-plagued Edward J. Sullivan Courthouse in Cambridge and hope to move prisoners housed in county jail at the facility to another location by the spring of 2013. |archive-date=January 30, 2018 |archive-url=https://web.archive.org/web/20180130091232/http://archive.boston.com/yourtown/news/cambridge/2011/11/state_advertising_22-story_sul.html |url-status=live }}</ref> by the Commonwealth of Massachusetts.<ref>{{Cite news |last=Ansari, Esq. |first=Maryam K. |date=December 19, 2012 |title=Cambridge Residents Contesting Plans for Sullivan Courthouse |work=FindLaw Network |publisher=Boston Real Estate Law News |agency=Thomson Reuters |url=http://bostonrealestatelawnews.com/2012/12/cambridge-residents-contesting-plans-for-sullivan-courthouse.html |access-date=February 10, 2018 |archive-date=January 30, 2018 |archive-url=https://web.archive.org/web/20180130014347/http://bostonrealestatelawnews.com/2012/12/cambridge-residents-contesting-plans-for-sullivan-courthouse.html |url-status=live }}</ref> Due to its transfer from state control,<ref>{{Cite news |last=Goodison |first=Donna |date=July 20, 2017 |title=Cambridge courthouse judged fit for redo |work=[[The Boston Herald|Boston Herald and Herald Media]] |url=http://www.bostonherald.com/business/real_estate/2017/07/cambridge_courthouse_judged_fit_for_redo |access-date=February 10, 2018 |quote=The Appeals Court upheld a 2015 Land Court decision that determined the former Edward J. Sullivan Courthouse, when transferred from state ownership to private ownership under Boston developer Leggat McCall Properties, would still be considered a legal, preexisting nonconforming structure despite losing its government immunity from zoning rules. |archive-date=January 30, 2018 |archive-url=https://web.archive.org/web/20180130145429/http://www.bostonherald.com/business/real_estate/2017/07/cambridge_courthouse_judged_fit_for_redo |url-status=live }}</ref> many local residents had tried to force the private developers to reduce the overall height of the structure.<ref>{{Cite news |last=Chesto |first=Jon |date=August 8, 2017 |title=A towering dilemma in East Cambridge |work=The Boston Globe |url=https://www.bostonglobe.com/business/talking-points/2017/08/08/towering-dilemma-east-cambridge/c2wZnnDecPvEiiHSoyH7EK/story.html |url-status=dead |url-access=subscription |access-date=February 10, 2018 |archive-url=https://web.archive.org/web/20170811191556/http://www.bostonglobe.com/business/talking-points/2017/08/08/towering-dilemma-east-cambridge/c2wZnnDecPvEiiHSoyH7EK/story.html |archive-date=August 11, 2017 |quote=The developers who want to remodel the imposing former courthouse tower in East Cambridge and enliven its ground floor had hoped an appeals court decision last month was the final green light they needed.}}</ref><ref>{{Cite web |last=Staff writer |date=July 20, 2017 |title=40 Thorndike Street |url=http://www.bldup.com/projects/40-thorndike-street |access-date=February 10, 2018 |website=Bldup.com |publisher=BLDUP |quote=Upcoming mixed-use development located steps from Kendall Square that will transform the existing 22-story Sullivan Courthouse and Middlesex Jail tower in East Cambridge into a 20-story mixed-use tower. The new 40 Thorndike Street will feature approximately 430,000 square feet of office, research & development space and 15,000 square feet of ground-floor retail, along with 24 apartment residences on lower floors. Lower office floors will be marketed to startup companies as innovation space. Retail will include a grocery store and a health club; a daycare could be included as well. |archive-date=January 30, 2018 |archive-url=https://web.archive.org/web/20180130013843/http://www.bldup.com/projects/40-thorndike-street |url-status=live }}</ref>

Even following the abolition of the executive branch for county government in Middlesex, communities are still granted a right by the Massachusetts state legislature to form their own regional compacts for sharing of services and costs thereof.

{| class="toccolours"
|-
|+ '''County government: Middlesex County'''
|- valign=top
! align=right | [[Court clerk|Clerk of Courts]]:
| [[Michael A. Sullivan (politician)|Michael A. Sullivan]]
|- valign=top
! align=right |  [[District attorney|District Attorney]]:
| [[Marian T. Ryan]]
|- valign=top
! align=right |  [[Recorder of deeds|Register of Deeds]]:
| Richard P. Howe, Jr. (North at Lowell)<br /> Maria C. Curtatone (South at Cambridge)
|- valign=top
! align=right | [[Probate|Register of Probate]]:
| Tara E. DeCristofaro
|- valign=top
! align=right | [[Sheriff|County Sheriff]]:
| [[Peter Koutoujian|Peter J. Koutoujian]]<ref>{{Cite web|url=http://middlesexsheriff.org/Biography.html|title=Peter J. Koutoujian : Biography|date=December 9, 2013|archive-url=https://web.archive.org/web/20131209050852/http://middlesexsheriff.org/Biography.html |accessdate=July 23, 2022|archive-date=December 9, 2013 }}</ref>
|- 
! colspan=2 | State government
|- valign=top
! align=right | [[Massachusetts House of Representatives|State Representative(s)]]:
| 37 Representatives<ref>{{Cite web |url=http://www.mass.gov/legis/repdis03.htm |title=Representative Districts |access-date=June 10, 2007 |archive-date=May 30, 2007 |archive-url=https://web.archive.org/web/20070530193736/http://www.mass.gov/legis/repdis03.htm |url-status=dead }}</ref>
|- valign=top
! align=right | [[Massachusetts Senate|State Senator(s)]]:
| 16 Senators<ref>{{Cite web |url=http://www.mass.gov/legis/sendis03.htm |title=Massachusetts General Court &ndash; Senatorial Districts |access-date=June 10, 2007 |archive-date=March 4, 2010 |archive-url=https://web.archive.org/web/20100304165150/http://www.mass.gov/legis/sendis03.htm |url-status=dead }}</ref>
|- valign=top
! align=right | [[Massachusetts Governor's Council|Governor's Councilor(s)]]:
| [[Robert L. Jubinville]] (D-2nd district)<br />[[Marilyn M. Petitto]] (D-3rd district)<br />[[Eileen R. Duff]] (D-5th district)<br />[[Terrence W. Kennedy]] (D-6th district)<br />[[Paul DePalo]] (D-7th district)
|-
! colspan=2 | Federal government
|- valign=top
! align=right | [[United States House of Representatives|U.S. Representative(s)]]:
| [[Jake Auchincloss]] (D-{{ushr|MA|4|C}})<br /> [[Lori Trahan]] (D-{{ushr|MA|3|C}})<br /> [[Seth Moulton]] (D-{{ushr|MA|6|C}})<br /> [[Katherine Clark]] (D-{{ushr|MA|5|C}})<br /> [[Ayanna Pressley]] (D-{{ushr|MA|7|C}})
|- valign=top
! align=right | [[United States Senate|U.S. Senators]]:
| [[Elizabeth Warren]] (D), [[Ed Markey]] (D)
|}

==Geography==
According to the [[U.S. Census Bureau]], the county has a total area of {{convert|847|sqmi}}, of which {{convert|818|sqmi}} is land and {{convert|29|sqmi}} (3.5%) is water.<ref name="GR1">{{cite web|url=https://www.census.gov/geo/maps-data/data/docs/gazetteer/counties_list_25.txt|publisher=United States Census Bureau|access-date=September 16, 2014|date=August 22, 2012|title=2010 Census Gazetteer Files|url-status=dead|archive-url=https://archive.today/20140914175857/http://www.census.gov/geo/maps-data/data/docs/gazetteer/counties_list_25.txt|archive-date=September 14, 2014}}</ref> It is the third-largest county in Massachusetts by land area.

It is bounded southeast by the [[Charles River]] and drained by the [[Merrimack River|Merrimack]], [[Nashua River|Nashua]], and [[Concord River|Concord]] rivers, and other streams.<ref>{{Cite AmCyc|wstitle=Middlesex (United States)|display=Middlesex: I. A N. E. county of Massachusetts}}</ref>

The [[MetroWest]] region comprises much of the southern portion of the county.

===Adjacent counties===
*[[Hillsborough County, New Hampshire]] (north)
*[[Essex County, Massachusetts|Essex County]] (northeast)
*[[Suffolk County, Massachusetts|Suffolk County]] (southeast)
*[[Norfolk County, Massachusetts|Norfolk County]] (south)
*[[Worcester County, Massachusetts|Worcester County]] (west)

===Transportation===
These routes pass through Middlesex County
*{{jct|state=MA|I|90}}, From Hopkinton to Newton
*{{jct|state=MA|I|93}}, From Somerville to Tewksbury
*{{jct|state=MA|I|95}}, From Newton to Wakefield 
*{{jct|state=MA|I|290}}, In Marlboro
*{{jct|state=MA|I|495}}, From Hopkinton to Tewksbury
*{{jct|state=MA|US|1}}, From Cambridge to Malden
*{{jct|state=MA|US|3}}/[[Massachusetts Route 3|Route 3]], From Cambridge to Tyngsborough
*{{jct|state=MA|US|20}}, From Marlborough to Watertown 
*{{jct|state=MA|MA|2}}, From Littleton to Cambridge 
*{{jct|state=MA|MA|2A}}, From Shirley to Cambridge
*{{jct|state=MA|MA|3A}}, From Burlington to Tyngsborough 
*{{jct|state=MA|MA|4}}, From Lexington-Arlington line to Chelmsford
*{{jct|state=MA|MA|9}}, From Framingham to Newton 
*{{jct|state=MA|MA|13}}, In Townsend 
*{{jct|state=MA|MA|16}}, From Holliston to Everett
*{{jct|state=MA|MA|27}}, From Sherborn to Chelmsford 
*{{jct|state=MA|MA|28}}, From Cambridge to North Reading
*{{jct|state=MA|MA|30}}, From Framingham to Newton 
*{{jct|state=MA|MA|31}}, In Ashby
*{{jct|state=MA|MA|38}}, From Somerville to Dracut
*{{jct|state=MA|MA|40}}, From Groton to Chelmsford 
*{{jct|state=MA|MA|60}}, From Waltham to Malden
*{{jct|state=MA|MA|62}}, From Hudson to North Reading
*{{jct|state=MA|MA|85}}, From Hopkinton to Hudson
*{{jct|state=MA|MA|99}}, From Everett to Melrose
*{{jct|state=MA|MA|110}}, From Ayer to Dracut
*{{jct|state=MA|MA|111}}, From Concord to Pepperell 
*{{jct|state=MA|MA|113}}, From Pepperell to Dracut
*{{jct|state=MA|MA|115}}, In Sherborn
*{{jct|state=MA|MA|117}}, From Stow to Waltham
*{{jct|state=MA|MA|119}}, From Concord to Ashby 
*{{jct|state=MA|MA|125}}, From Wilmington to North Reading 
*{{jct|state=MA|MA|126}}, From Holliston to Concord
*{{jct|state=MA|MA|128}}, From Newton to Wakefield
*{{jct|state=MA|MA|129}}, From Chelmsford to Wakefield
*{{jct|state=MA|MA|133}}, From Lowell to Tewksbury
*{{jct|state=MA|MA|135}}, From Hopkinton to Natick
*{{jct|state=MA|MA|225}}, From Shirley to Lexington

===National protected areas===
* [[Assabet River National Wildlife Refuge]]
* [[Great Meadows National Wildlife Refuge]]
* [[Longfellow House–Washington's Headquarters National Historic Site]]
* [[Lowell National Historical Park]]
* [[Minute Man National Historical Park]]
* [[Oxbow National Wildlife Refuge]] (part)

==Demographics==
{{US Census population
|1790= 42769
|1800= 46928
|1810= 52789
|1820= 61472
|1830= 77961
|1840= 106611
|1850= 161383
|1860= 216354
|1870= 274353
|1880= 317830
|1890= 431167
|1900= 565696
|1910= 669915
|1920= 778352
|1930= 934924
|1940= 971390
|1950= 1064569
|1960= 1238742
|1970= 1397268
|1980= 1367034
|1990= 1398468
|2000= 1465396
|2010= 1503085
|2020= 1632002
|estyear=2024
|estimate=1668956
|estref=<ref name="USCensusEst2023">{{cite web|url=https://www.census.gov/programs-surveys/popest/data/tables.html|title=Annual Estimates of the Resident Population for Counties: April 1, 2020 to July 1, 2023|publisher=United States Census Bureau|access-date=April 3, 2024}}</ref>
|align-fn=center
|footnote=U.S. Decennial Census<ref>{{cite web|url=https://www.census.gov/programs-surveys/decennial-census.html|title=U.S. Decennial Census|publisher=United States Census Bureau|access-date=September 16, 2014|archive-date=July 1, 2021|archive-url=https://web.archive.org/web/20210701194652/https://www.census.gov/programs-surveys/decennial-census.html|url-status=live}}</ref><br />1790-1960<ref>{{cite web|url=http://mapserver.lib.virginia.edu/|title=Historical Census Browser|publisher=University of Virginia Library|access-date=September 16, 2014|archive-date=August 11, 2012|archive-url=https://web.archive.org/web/20120811110448/http://mapserver.lib.virginia.edu/|url-status=live}}</ref> 1900-1990<ref>{{cite web|url=https://www.census.gov/population/cencounts/ma190090.txt|title=Population of Counties by Decennial Census: 1900 to 1990|publisher=United States Census Bureau|access-date=September 16, 2014|archive-date=April 28, 2015|archive-url=https://web.archive.org/web/20150428025655/http://www.census.gov/population/cencounts/ma190090.txt|url-status=live}}</ref><br />1990-2000<ref>{{cite web|url=https://www.census.gov/population/www/cen2000/briefs/phc-t4/tables/tab02.pdf|title=Census 2000 PHC-T-4. Ranking Tables for Counties: 1990 and 2000|publisher=United States Census Bureau|access-date=September 16, 2014|archive-date=December 18, 2014|archive-url=https://web.archive.org/web/20141218203824/http://www.census.gov/population/www/cen2000/briefs/phc-t4/tables/tab02.pdf|url-status=live}}</ref> 2010-2020<ref>{{cite web|url=https://www.census.gov/library/visualizations/interactive/2020-population-and-housing-state-data.html|title=2020 Population and Housing State Data|publisher=United States Census Bureau|access-date=August 15, 2021|archive-date=August 12, 2021|archive-url=https://web.archive.org/web/20210812173619/https://www.census.gov/library/visualizations/interactive/2020-population-and-housing-state-data.html|url-status=live}}</ref>
}}

In 2006, Middlesex County contained the tenth most millionaires of any county in the United States.<ref name="millionaires">{{cite news | url=https://money.cnn.com/2006/03/28/news/economy/millionaires/ | work=CNN | first=Jeanne | last=Sahadi | title=Top 10 millionaire counties | date=March 28, 2006 | access-date=August 3, 2020 | archive-date=October 30, 2020 | archive-url=https://web.archive.org/web/20201030082932/https://money.cnn.com/2006/03/28/news/economy/millionaires/ | url-status=live }}</ref>

As of the [[2010 United States census]], there were 1,503,085 people, 580,688 households, and 366,656 families residing in the county.<ref name="census-dp1">{{cite web
  |url=http://factfinder.census.gov/bkmk/table/1.0/en/DEC/10_DP/DPDP1/0500000US25017
  |title=DP-1 Profile of General Population and Housing Characteristics: 2010 Demographic Profile Data
  |access-date=January 12, 2016
|publisher=[[United States Census Bureau]]
  |archive-url=https://archive.today/20200213031244/http://factfinder.census.gov/bkmk/table/1.0/en/DEC/10_DP/DPDP1/0500000US25017
  |archive-date=February 13, 2020
|url-status=dead
  }}</ref> The population density was {{convert|1,837.9|PD/sqmi}}. There were 612,004 housing units at an average density of {{convert|748.3|/sqmi}}.<ref name="census-density">{{cite web
  |url=http://factfinder.census.gov/bkmk/table/1.0/en/DEC/10_SF1/GCTPH1.CY07/0500000US25017
  |access-date=January 12, 2016
|title=Population, Housing Units, Area, and Density: 2010 - County
  |publisher=[[United States Census Bureau]]
  |archive-url=https://archive.today/20200213184155/http://factfinder.census.gov/bkmk/table/1.0/en/DEC/10_SF1/GCTPH1.CY07/0500000US25017
  |archive-date=February 13, 2020
|url-status=dead
  }}</ref> The racial makeup of the county was 80.0% white, 9.3% Asian, 4.7% black or African American, 0.2% American Indian, 3.3% from other races, and 2.5% from two or more races. Those of Hispanic or Latino origin made up 6.5% of the population.<ref name="census-dp1"/>

The largest ancestry groups were:<ref name="census-dp2">{{cite web
  |url=http://factfinder.census.gov/bkmk/table/1.0/en/ACS/10_5YR/DP02/0500000US25017
  |title=DP02 SELECTED SOCIAL CHARACTERISTICS IN THE UNITED STATES – 2006-2010 American Community Survey 5-Year Estimates
  |access-date=January 12, 2016
|publisher=[[United States Census Bureau]]
  |archive-url=https://archive.today/20200213032015/http://factfinder.census.gov/bkmk/table/1.0/en/ACS/10_5YR/DP02/0500000US25017
  |archive-date=February 13, 2020
|url-status=dead
  }}</ref>
 {{Div col|colwidth=15em}}
*23.5% [[Irish Americans|Irish]] 
*16.2% [[Italian Americans|Italian]]
*11.2% [[English Americans|English]]
*7.1% [[German Americans|German]]
*5.6% [[French Americans|French]]
*4.0% [[Polish Americans|Polish]]
*3.6% [[French Canadian Americans|French Canadian]]
*3.2% [[Chinese Americans|Chinese]]
*3.1% [[Portuguese Americans|Portuguese]]
*2.9% [[American ancestry|American]]
*2.7% [[Scottish Americans|Scottish]]
*2.6% [[Russian Americans|Russian]]
*2.5% [[Indian Americans|Indian]]
*2.4% [[Brazilian Americans|Brazilian]]
*2.0% [[Scotch-Irish Americans|Scotch-Irish]]
*2.0% [[Puerto Rican Americans|Puerto Rican]]
*1.7% [[Swedish Americans|Swedish]]
*1.6% [[Greek Americans|Greek]]
*1.2% [[Subsaharan Africa|Sub-Saharan African]]
*1.2% [[Haitian Americans|Haitian]]
*1.2% [[Armenian Americans|Armenian]]
*1.1% [[Canadian Americans|Canadian]]
*1.0% [[Cambodian Americans|Cambodian]]
*1.0% [[Arab Americans|Arab]]
{{div col end}}

Of the 580,688 households, 31.0% had children under the age of 18 living with them, 49.5% were married couples living together, 10.1% had a female householder with no husband present, 36.9% were non-families, and 27.8% of all households were made up of individuals. The average household size was 2.49 and the average family size was 3.10. The median age was 38.5 years.<ref name="census-dp1"/>

The median income for a household in the county was $77,377 and the median income for a family was $97,382. Males had a median income of $64,722 versus $50,538 for females. The per capita income for the county was $40,139. About 5.1% of families and 7.6% of the population were below the [[poverty line]], including 8.0% of those under age 18 and 8.0% of those age 65 or over.<ref name="census-dp3">{{cite web
  |url=http://factfinder.census.gov/bkmk/table/1.0/en/ACS/10_5YR/DP03/0500000US25017
  |title=DP03 SELECTED ECONOMIC CHARACTERISTICS – 2006-2010 American Community Survey 5-Year Estimates
  |access-date=January 12, 2016
|publisher=[[United States Census Bureau]]
  |archive-url=https://archive.today/20200213020651/http://factfinder.census.gov/bkmk/table/1.0/en/ACS/10_5YR/DP03/0500000US25017
  |archive-date=February 13, 2020
|url-status=dead
  }}</ref>

79.6% spoke only [[english language|English]] at home, while 4.3% spoke [[spanish language|Spanish]], 2.7% [[portuguese language|Portuguese]], 1.6% [[italian language|Italian]], 1.6% [[chinese language|Chinese]] including [[standard mandarin|Mandarin]] and other Chinese dialects, and 1.5% spoke [[french language|French]].

Middlesex County has the largest Irish-American population of any U.S. county with a plurality of Irish ancestry.<ref>{{cite web|url=https://www.census.gov/Press-Release/www/releases/archives/facts_for_features_special_editions/006328.html|archive-url=https://web.archive.org/web/20060225100820/http://www.census.gov/Press-Release/www/releases/archives/facts_for_features_special_editions/006328.html|archive-date=February 25, 2006|title=US Census Press Releases|date=February 25, 2006}}</ref><ref>{{Cite web |url=https://www.census.gov/popest/data/counties/totals/2011/tables/CO-EST2011-01-25.csv |title=Archived copy |access-date=December 7, 2017 |archive-url=https://web.archive.org/web/20151012164941/http://www.census.gov/popest/data/counties/totals/2011/tables/CO-EST2011-01-25.csv |archive-date=October 12, 2015 |url-status=dead }}</ref>
[[File:Middlesex County MA population density.png|thumb|Population density of Middlesex County by census block (2020)<ref>{{Citation |title=TIGER/Line Shapefile, 2020, State, Massachusetts, 2020 Census Block |url=https://catalog.data.gov/dataset/tiger-line-shapefile-2020-state-massachusetts-2020-census-block |access-date=2025-05-22 |publisher=U.S. Department of Commerce, U.S. Census Bureau, Geography Division, Spatial Data Collection and Products Branch (Point of Contact) |language=en}}</ref>]]

===Demographic breakdown by town===

====Income====
{{See also|List of Massachusetts locations by per capita income}}
The ranking of unincorporated communities that are included on the list is reflective if the census-designated locations and villages were included as cities or towns. Data is from the 2007-2011 American Community Survey 5-Year Estimates.<ref>{{cite web |url=http://factfinder.census.gov/faces/tableservices/jsf/pages/productview.xhtml?pid=ACS_11_5YR_DP03&prodType=table|archive-url=https://archive.today/20200212213610/http://factfinder.census.gov/faces/tableservices/jsf/pages/productview.xhtml?pid=ACS_11_5YR_DP03&prodType=table|url-status=dead|archive-date=February 12, 2020|title=SELECTED ECONOMIC CHARACTERISTICS 2007-2011 American Community Survey 5-Year Estimates|publisher=U.S. Census Bureau|access-date=January 26, 2013}}</ref><ref>{{cite web |url=http://factfinder.census.gov/faces/tableservices/jsf/pages/productview.xhtml?pid=ACS_11_5YR_DP05&prodType=table|archive-url=https://archive.today/20200212212105/http://factfinder.census.gov/faces/tableservices/jsf/pages/productview.xhtml?pid=ACS_11_5YR_DP05&prodType=table|url-status=dead|archive-date=February 12, 2020|title=ACS DEMOGRAPHIC AND HOUSING ESTIMATES 2007-2011 American Community Survey 5-Year Estimates|publisher=U.S. Census Bureau |access-date=January 26, 2013}}</ref><ref>{{cite web |url=http://factfinder.census.gov/faces/tableservices/jsf/pages/productview.xhtml?pid=ACS_11_5YR_S1101&prodType=table|archive-url=https://archive.today/20200212212620/http://factfinder.census.gov/faces/tableservices/jsf/pages/productview.xhtml?pid=ACS_11_5YR_S1101&prodType=table|url-status=dead|archive-date=February 12, 2020|title=HOUSEHOLDS AND FAMILIES 2007-2011 American Community Survey 5-Year Estimates|publisher=U.S. Census Bureau |access-date=January 26, 2013}}</ref>
{| class="wikitable sortable"
|- valign=bottom
! Rank
! Town
! 
! Per capita<br />income
! Median<br />household<br />income
! Median<br />family<br />income
! Population
! Number of<br />households
|-
| 1
| [[Weston, Massachusetts|Weston]]
| Town
| $96,475
| $180,815
| $220,441
| 11,229
| 3,557
|-
| 2
| [[Sherborn, Massachusetts|Sherborn]]
| Town
| $70,983
| $152,083
| $183,456
| 4,102
| 1,463
|-
| 3
| [[Wayland, Massachusetts|Wayland]]
| Town
| $70,185
| $125,076
| $151,812
| 12,939
| 4,902
|-
| 4
| [[Carlisle, Massachusetts|Carlisle]]
| Town
| $68,060
| $159,063
| $171,167
| 4,814
| 1,612
|-
| 5
| [[Lexington, Massachusetts|Lexington]]
| Town
| $67,584
| $136,610
| $158,888
| 31,129
| 11,411
|-
| 6
| [[Concord, Massachusetts|Concord]]
| Town
| $67,374
| $127,951
| $156,352
| 17,523
| 6,197
|-
| 7
| [[Winchester, Massachusetts|Winchester]]
| Town
| $65,172
| $127,665
| $160,706
| 21,205
| 7,611
|-
| 8
| [[Sudbury, Massachusetts|Sudbury]]
| Town
| $63,862
| $159,713
| $173,587
| 17,482
| 5,613
|-
| 9
| [[Newton, Massachusetts|Newton]]
| City
| $60,323
| $109,724
| $141,944
| 84,583
| 30,735
|-
| 10
| [[Lincoln, Massachusetts|Lincoln]]
| Town
| $57,471
| $130,523
| $141,667
| 6,480
| 2,150
|-
| 11
| [[Hopkinton, Massachusetts|Hopkinton]]
| Town
| $56,939
| $126,350
| $149,213
| 14,691
| 4,893
|-
| 
| ''[[Chestnut Hill, Massachusetts|Chestnut Hill]] (02467)''
| [[ZIP Code Tabulation Area|ZCTA]]
| $55,947
| $114,140
| $151,375
| 21,952
| 6,237
|-
| 12
| [[Belmont, Massachusetts|Belmont]]
| Town
| $54,361
| $99,529
| $121,250
| 24,548
| 9,465
|-
| 
| ''[[Cochituate, Massachusetts|Cochituate]]''
| CDP
| $52,936
| $107,589
| $133,082
| 6,384
| 2,496
|-
| 13
| [[Boxborough, Massachusetts|Boxborough]]
| Town
| $51,159
| $103,918
| $134,583
| 4,957
| 1,984
|-
| 14
| [[Acton, Massachusetts|Acton]]
| Town
| $49,603
| $109,491
| $135,000
| 21,656
| 7,924
|-
| 15
| [[Natick, Massachusetts|Natick]]
| Town
| $49,012
| $90,046
| $117,259
| 32,729
| 13,440
|-
| 16
| [[Bedford, Massachusetts|Bedford]]
| Town
| $48,899
| $101,886
| $128,448
| 13,192
| 4,951
|-
| 17
| [[Stow, Massachusetts|Stow]]
| Town
| $48,448
| $112,130
| $132,061
| 6,488
| 2,328
|-
| 
| ''[[West Concord, Massachusetts|West Concord]]''
| CDP
| $47,633
| $103,693
| $145,242
| 6,134
| 2,069
|-
| 18
| [[Holliston, Massachusetts|Holliston]]
| Town
| $47,624
| $107,374
| $125,236
| 13,512
| 4,918
|-
| 19
| [[Westford, Massachusetts|Westford]]
| Town
| $47,587
| $119,511
| $135,000
| 21,716
| 7,308
|-
| 20
| [[Arlington, Massachusetts|Arlington]]
| Town
| $47,571
| $85,059
| $107,862
| 42,570
| 19,007
|-
| 21
| [[Groton, Massachusetts|Groton]]
| Town
| $47,003
| $117,903
| $135,143
| 10,478
| 3,650
|-
| 22
| [[Ashland, Massachusetts|Ashland]]
| Town
| $46,626
| $93,770
| $116,799
| 16,305
| 6,484
|-
| 23
| [[Cambridge, Massachusetts|Cambridge]]
| City
| $46,242
| $69,017
| $94,536
| 104,322
| 45,386
|-
| 24
| [[Reading, Massachusetts|Reading]]
| Town
| $44,949
| $99,131
| $117,477
| 24,504
| 9,055
|-
| 25
| [[Chelmsford, Massachusetts|Chelmsford]]
| Town
| $42,535
| $90,895
| $110,967
| 33,610
| 13,304
|-
| 26
| [[North Reading, Massachusetts|North Reading]]
| Town
| $42,256
| $104,069
| $116,729
| 14,703
| 5,077
|-
| 27
| [[Dunstable, Massachusetts|Dunstable]]
| Town
| $41,937
| $109,205
| $121,406
| 3,128
| 1,087
|-
| 28
| [[Littleton, Massachusetts|Littleton]]
| Town
| $41,815
| $103,438
| $114,094
| 8,810
| 3,198
|-
| 
| ''Middlesex County''
| County
| $41,453
| $79,691
| $100,267
| 1,491,762
| 577,349
|-
| 29
| [[Watertown, Massachusetts|Watertown]]
| City
| $41,090
| $76,718
| $90,521
| 31,792
| 14,042
|-
| 30
| [[Wakefield, Massachusetts|Wakefield]]
| Town
| $40,227
| $85,379
| $112,293
| 24,794
| 10,058
|-
| 31
| [[Burlington, Massachusetts|Burlington]]
| Town
| $40,083
| $92,236
| $107,339
| 24,207
| 9,177
|-
| 32
| [[Melrose, Massachusetts|Melrose]]
| City
| $39,873
| $84,599
| $105,893
| 26,864
| 10,963
|-
| 
| ''[[Groton (CDP), Massachusetts|Groton]]''
| CDP
| $39,208
| $55,446
| $127,708
| 1,077
| 507
|-
| 
| ''[[Hopkinton (CDP), Massachusetts|Hopkinton]]''
| CDP
| $38,507
| $71,536
| $105,882
| 2,110
| 877
|-
| 33
| [[Tyngsborough, Massachusetts|Tyngsborough]]
| Town
| $38,067
| $101,103
| $111,780
| 11,198
| 3,797
|-
| 34
| [[Stoneham, Massachusetts|Stoneham]]
| Town
| $37,573
| $77,476
| $95,490
| 21,413
| 8,909
|-
| 35
| [[Marlborough, Massachusetts|Marlborough]]
| City
| $37,314
| $72,853
| $94,770
| 38,087
| 15,856
|-
| 36
| [[Wilmington, Massachusetts|Wilmington]]
| Town
| $37,084
| $100,861
| $107,436
| 22,116
| 7,200
|-
| 37
| [[Pepperell, Massachusetts|Pepperell]]
| Town
| $37,081
| $84,618
| $102,946
| 11,407
| 4,125
|-
| 38
| [[Maynard, Massachusetts|Maynard]]
| Town
| $36,818
| $77,255
| $93,116
| 10,083
| 4,222
|-
| 39
| [[Tewksbury, Massachusetts|Tewksbury]]
| Town
| $36,509
| $86,378
| $103,008
| 28,778
| 10,670
|-
| 40
| [[Hudson, Massachusetts|Hudson]]
| Town
| $36,141
| $76,714
| $95,746
| 18,845
| 7,679
|-
| 
| ''[[Pepperell (CDP), Massachusetts|Pepperell]]''
| CDP
| $35,227
| $68,500
| $65,417
| 2,239
| 852
|-
| 
| ''[[Massachusetts]]''
| State
| $35,051
| $65,981
| $83,371
| 6,512,227
| 2,522,409
|-
| 41
| [[Medford, Massachusetts|Medford]]
| City
| $34,615
| $72,033
| $83,078
| 55,843
| 22,461
|-
| 
| ''[[Hudson (CDP), Massachusetts|Hudson]]''
| CDP
| $33,734
| $68,812
| $86,216
| 14,797
| 6,129
|-
| 42
| [[Woburn, Massachusetts|Woburn]]
| City
| $33,725
| $72,540
| $87,924
| 37,831
| 15,357
|-
| 43
| [[Waltham, Massachusetts|Waltham]]
| City
| $33,717
| $68,326
| $82,233
| 60,209
| 23,520
|-
| 44
| [[Framingham, Massachusetts|Framingham]]
| City
| $33,665
| $66,047
| $86,977
| 67,844
| 26,167
|-
| 
| ''[[Pinehurst, Massachusetts|Pinehurst]]''
| CDP
| $33,572
| $95,038
| $100,650
| 7,289
| 2,414
|-
| 45
| [[Billerica, Massachusetts|Billerica]]
| Town
| $33,347
| $88,531
| $98,371
| 39,930
| 13,859
|-
| 46
| [[Somerville, Massachusetts|Somerville]]
| City
| $32,785
| $64,480
| $71,518
| 75,566
| 31,476
|-
| 47
| [[Ashby, Massachusetts|Ashby]]
| Town
| $32,434
| $82,614
| $84,655
| 3,030
| 1,060
|-
| 48
| [[Ayer, Massachusetts|Ayer]]
| Town
| $32,179
| $54,899
| $78,947
| 7,370
| 3,063
|-
| 
| ''[[Littleton Common, Massachusetts|Littleton Common]]''
| CDP
| $32,058
| $80,352
| $105,217
| 2,907
| 1,131
|-
| 49
| [[Dracut, Massachusetts|Dracut]]
| Town
| $31,533
| $71,824
| $88,281
| 29,249
| 11,173
|-
| 50
| [[Townsend, Massachusetts|Townsend]]
| Town
| $31,201
| $76,250
| $91,023
| 8,906
| 3,114
|-
| 
| ''[[East Pepperell, Massachusetts|East Pepperell]]''
| CDP
| $30,475
| $74,077
| $79,104
| 2,195
| 811
|-
| 
| ''[[Ayer (CDP), Massachusetts|Ayer]]''
| CDP
| $30,456
| $42,055
| $79,708
| 2,573
| 1,205
|-
| 
| ''[[United States]]''
| Country
| $27,915
| $52,762
| $64,293
| 306,603,772
| 114,761,359
|-
| 
| ''[[Townsend (CDP), Massachusetts|Townsend]]''
| CDP
| $27,166
| $51,512
| $71,023
| 968
| 453
|-
| 51
| [[Malden, Massachusetts|Malden]]
| City
| $26,893
| $52,842
| $65,763
| 58,821
| 23,422
|-
| 
| ''[[Shirley (CDP), Massachusetts|Shirley]]''
| CDP
| $24,943
| $41,250
| $41,838
| 1,330
| 593
|-
| 52
| [[Everett, Massachusetts|Everett]]
| City
| $24,575
| $48,319
| $58,045
| 41,079
| 15,681
|-
| 53
| [[Shirley, Massachusetts|Shirley]]
| Town
| $24,427
| $71,146
| $78,493
| 7,235
| 2,189
|-
| 54
| [[Lowell, Massachusetts|Lowell]]
| City
| $23,600
| $51,471
| $57,934
| 105,860
| 39,399
|-
| 
| ''[[Devens, Massachusetts|Devens]]''
| CDP
| $13,933
| $72,986
| $73,194
| 1,704
| 113
|}

==Law enforcement==
{{Infobox law enforcement agency
| agencyname      = Middlesex Sheriff's Office
| nativename      =
| nativenamea     =
| nativenamer     =
| commonname      =
| abbreviation    = MSO
| fictional       =
| patch           = MiddlesexSheriffpatch.jpg
| patchcaption    = Patch of the Middlesex Sheriff's Office
| logo            =
| logocaption     =
| badge           =
| badgecaption    =
| flag            =
| flagcaption     =
| imagesize       =
| motto           =
| mottotranslated =
| mission         =
| formedyear      = {{start date and age|1692}}
| formedmonthday  =
| preceding1      =
| dissolved       =
|
| employees       = 800
| volunteers      =
| budget          = $60 Million
| nongovernment   =
| country         = United States
| countryabbr     = U.S.
| national        =
| federal         =
| international   =
| divtype         = Commonwealth
| divname         = Massachusetts
| divdab          =
| subdivtype      =
| subdivname      =
| subdivdab       =
| map             =
| mapcaption      =
| sizearea        =
| sizepopulation  =
| legaljuris      = County of [[Middlesex, Massachusetts]]
| governingbody   =
| governingbodyscnd =
| constitution1   =
| police          = Yes
| local           = Yes
| military        =
| provost         =
| gendarmerie     =
| religious       =
| speciality      =
| secret          =
| overviewtype    =
| overviewbody    =
| headquarters    = [[Medford, Massachusetts]]
| hqlocmap        =
| hqlocleft       =
| hqloctop        =
| hqlocmappoptitle =
| sworntype       = Deputy Sheriff/Correction Officer
| sworn           =
| unsworntype     =
| unsworn         =
| multinational   =
| electeetype     = [[Sheriff]]
| minister1name   = [[Peter Koutoujian]]
| minister1pfo    =
| chief1name      =
| chief1position  =
| parentagency    =
| child1agency    =
| unittype        =
| unitname        =
| officetype      =
| officename      =
| provideragency  =
| uniformedas     =
| stationtype     =
| facilities      =
| airbases        =
| lockuptype      =
| lockups         = 2
| vehicle1type    = Patrol Vehicle
| vehicles1       = [[Ford Crown Victoria Police Interceptor]]
| boat1type       =
| boats1          = 
| aircraft1type   =
| aircraft1       =
| animal1type     =
| animals1        =
| animal2type     =
| animals2        =
| person1name     =
| person1reason   =
| person1type     =
| programme1      =
| activity1name   =
| activitytype    =
| anniversary1    =
| award1          =
| website         =
| footnotes       =
| reference       =
}}

The primary responsibility of the Middlesex Sheriff's Office is oversight of the [[Middlesex House of Correction and Jail]] in [[Billerica, Massachusetts|Billerica]]. It formerly ran the [[Middlesex Jail]] in [[Cambridge, Massachusetts|Cambridge]], which closed on June 28, 2014. In addition, the Sheriff's Office operates the Office of Civil Process and, the Lowell Community Counseling Centers, and crime prevention and community service programs. The office of sheriff was created in 1692, making it one of the oldest law enforcement agencies in the United States. The sheriff is elected to a 6-year term.<ref>{{Cite web |title=Middlesex Sheriff |url=https://www.middlesexsheriff.org/ |access-date=March 17, 2022 |website=Middlesexsheriff.org |archive-date=March 14, 2022 |archive-url=https://web.archive.org/web/20220314200932/https://www.middlesexsheriff.org/ |url-status=live }}</ref>

Notable sheriffs include:<ref name="Edward M. Burns, Esq"/>
{{div col}}
* Col. [[James Prescott (sheriff)|James Prescott]] (1775–1781)
* Col. [[Loammi Baldwin]] (1781–1794)
* Col. [[Samuel Chandler]] (1841–1851)
* [[Charles Kimball (sheriff)|Charles Kimball]] (1859–1879)
* [[John J. Buckley (sheriff)|John J. Buckley]] (1970–1980)
* [[John P. McGonigle]] (1985–1994)
* [[James DiPaola]] (1996–2010)
* [[John Granara]] ''(Special)'' (2010–2011)
* [[Peter Koutoujian]]  (2011–Present)
{{div col end}}

==Politics==
{| class=wikitable
! colspan = 6 | Voter registration and party enrollment as of August 2024<ref name="Voters">{{cite web |title=The Commonwealth of Massachusetts |url=https://www.sec.state.ma.us/divisions/elections/download/research-and-statistics/enrolment_count_20240903.pdf |website=Secretary of the Commonwealth of Massachusetts |access-date=October 11, 2024 |date=August 24, 2024}}</ref>
|-
| {{party color cell|Independent Party (United States)}}
| Unenrolled
| align = center | {{formatnum: 712,349}}
| align = center | {{Percentage |692,606 |1,108,860 |2}}
|-
| {{party color cell|Democratic Party (United States)}}
| [[Democratic Party (United States)|Democratic]]
| align = center | {{formatnum: 327,852}}
| align = center | {{Percentage |327,852 |1,127,675 |2}}
|-
| {{party color cell|Republican Party (United States)}}
| [[Republican Party (United States)|Republican]]
| align = center | {{formatnum: 77,758}}
| align = center | {{Percentage |77,758 |1,127,675 |2}}
|-
| {{party color cell|Libertarian Party (United States)}}
| [[Libertarian Party (United States)|Libertarian]]
| align = center | {{formatnum: 3,095}}
| align = center | {{Percentage |3,095 |1,127,675 |2}}
|-
| {{party color cell|Independent Party (United States)}}
| [[Third party (U.S. politics)|Other parties]]
| align = center | {{formatnum: 6,641}}
| align = center | {{Percentage |6,641 |1,127,675 |2}}
|-
! colspan = 2 | Total
! align = center | {{formatnum:1127675}}
! align = center | {{Percentage |100}}
|}
Prior to 1960, Middlesex County was a Republican Party stronghold, backing only two Democratic Party presidential candidates from 1856 to 1956. From the 1960 election the trend reversed; the county has exclusively supported Democratic presidential candidates. This has intensified in recent decades, as [[George H. W. Bush]] in 1988 was the most recent Republican presidential candidate to receive over 40 percent of the county's votes and [[Mitt Romney]] in 2012 the last Republican to receive over 30 percent. In 2020, [[Joe Biden]] won 71% of the county’s votes, the highest share for any presidential candidate since 1964.
{{clear}}

{{PresHead|place=Middlesex County, Massachusetts|source=<ref>{{cite web|url=http://uselectionatlas.org/RESULTS|title=Dave Leip's Atlas of U.S. Presidential Elections|first=David|last=Leip|website=uselectionatlas.org|access-date=July 10, 2017|archive-date=March 23, 2018|archive-url=https://web.archive.org/web/20180323225526/https://uselectionatlas.org/RESULTS/|url-status=live}}</ref>}}
<!-- PresRow should be {{PresRow|Year|Winning party|GOP vote #|Dem vote #|3rd party vote #|State}} -->
{{PresRow|2024|Democratic|235,118|554,471|25,243|Massachusetts}}
{{PresRow|2020|Democratic|226,956|617,196|19,425|Massachusetts}}
{{PresRow|2016|Democratic|219,793|520,360|56,582|Massachusetts}}
{{PresRow|2012|Democratic|267,321|471,804|15,045|Massachusetts}}
{{PresRow|2008|Democratic|245,766|464,484|15,781|Massachusetts}}
{{PresRow|2004|Democratic|237,815|440,862|10,283|Massachusetts}}
{{PresRow|2000|Democratic|198,914|404,043|54,091|Massachusetts}}
{{PresRow|1996|Democratic|169,926|398,190|59,861|Massachusetts}}
{{PresRow|1992|Democratic|193,703|343,994|151,756|Massachusetts}}
{{PresRow|1988|Democratic|290,352|361,563|10,713|Massachusetts}}
{{PresRow|1984|Democratic|319,604|325,065|2,085|Massachusetts}}
{{PresRow|1980|Democratic|256,999|270,751|109,929|Massachusetts}}
{{PresRow|1976|Democratic|260,044|359,919|23,419|Massachusetts}}
{{PresRow|1972|Democratic|269,064|345,343|3,244|Massachusetts}}
{{PresRow|1968|Democratic|188,304|370,310|18,982|Massachusetts}}
{{PresRow|1964|Democratic|134,729|439,790|2,291|Massachusetts}}
{{PresRow|1960|Democratic|246,126|356,130|1,260|Massachusetts}}
{{PresRow|1956|Republican|343,125|216,668|1,580|Massachusetts}}
{{PresRow|1952|Republican|316,069|236,910|1,626|Massachusetts}}
{{PresRow|1948|Democratic|228,262|248,240|9,406|Massachusetts}}
{{PresRow|1944|Republican|236,102|210,253|725|Massachusetts}}
{{PresRow|1940|Republican|242,658|218,663|2,116|Massachusetts}}
{{PresRow|1936|Republican|199,704|189,512|30,304|Massachusetts}}
{{PresRow|1932|Republican|184,486|174,257|7,008|Massachusetts}}
{{PresRow|1928|Republican|189,189|173,339|1,313|Massachusetts}}
{{PresRow|1924|Republican|162,530|64,544|28,161|Massachusetts}}
{{PresRow|1920|Republican|156,636|61,661|5,781|Massachusetts}}
{{PresRow|1916|Republican|60,802|49,844|2,426|Massachusetts}}
{{PresRow|1912|Democratic|30,511|36,689|35,667|Massachusetts}}
{{PresRow|1908|Republican|58,672|31,362|5,853|Massachusetts}}
{{PresRow|1904|Republican|55,704|32,889|3,275|Massachusetts}}
{{PresRow|1900|Republican|49,638|29,476|2,841|Massachusetts}}
{{PresRow|1896|Republican|57,281|19,591|3,394|Massachusetts}}
{{PresRow|1892|Republican|40,375|34,769|1,946|Massachusetts}}
{{PresRow|1888|Republican|35,768|28,570|1,519|Massachusetts}}
{{PresRow|1884|Republican|27,654|22,206|7,157|Massachusetts}}
{{PresRow|1880|Republican|30,339|19,801|1,013|Massachusetts}}
{{PresRow|1876|Republican|27,304|19,561|193|Massachusetts}}
{{PresRow|1872|Republican|26,570|12,434|0|Massachusetts}}
{{PresRow|1868|Republican|24,694|12,454|0|Massachusetts}}
|}

<!-- Please leave this blank space here, otherwise the table above obscures the heading below (even when hidden) -->

==Communities==
[[File:Map of Middlesex County, Massachusetts, by Geo. H. Walker & Co., 1889.jpg|thumb|1889 map of Middlesex County]]
[[File:Middlesex County Massachusetts incorporated and unincorporated areas Cambridge highlighted.svg|thumb|Map of Middlesex County, with Cambridge highlighted]]
Most municipalities in Middlesex County have a [[New England town|town]] form of government; the remainder are cities, and are so designated on this list. Villages listed below are census or postal divisions but have no separate corporate or statutory existence from the cities and towns in which they are located.

===Cities===
{{div col|colwidth=22em}}
*[[Cambridge, Massachusetts|Cambridge]] (traditional county seat) [[de jure]]
*[[Everett, Massachusetts|Everett]]
*[[Framingham, Massachusetts|Framingham]]
*[[Lowell, Massachusetts|Lowell]] (traditional county seat)
*[[Malden, Massachusetts|Malden]]
*[[Marlborough, Massachusetts|Marlborough]]
*[[Medford, Massachusetts|Medford]]
*[[Melrose, Massachusetts|Melrose]]
*[[Newton, Massachusetts|Newton]]
*[[Somerville, Massachusetts|Somerville]]
*[[Waltham, Massachusetts|Waltham]]
*[[Watertown, Massachusetts|Watertown]]
*[[Woburn, Massachusetts|Woburn]]
{{div col end}}

===Towns===
{{div col|colwidth=12em}}
*[[Acton, Massachusetts|Acton]]
*[[Arlington, Massachusetts|Arlington]]
*[[Ashby, Massachusetts|Ashby]]
*[[Ashland, Massachusetts|Ashland]]
*[[Ayer, Massachusetts|Ayer]]
*[[Bedford, Massachusetts|Bedford]]
*[[Belmont, Massachusetts|Belmont]]
*[[Billerica, Massachusetts|Billerica]]
*[[Boxborough, Massachusetts|Boxborough]]
*[[Burlington, Massachusetts|Burlington]]
*[[Carlisle, Massachusetts|Carlisle]]
*[[Chelmsford, Massachusetts|Chelmsford]]
*[[Concord, Massachusetts|Concord]]
*[[Dracut, Massachusetts|Dracut]]
*[[Dunstable, Massachusetts|Dunstable]]
*[[Groton, Massachusetts|Groton]]
*[[Holliston, Massachusetts|Holliston]]
*[[Hopkinton, Massachusetts|Hopkinton]]
*[[Hudson, Massachusetts|Hudson]]
*[[Lexington, Massachusetts|Lexington]]
*[[Lincoln, Massachusetts|Lincoln]]
*[[Littleton, Massachusetts|Littleton]]
*[[Maynard, Massachusetts|Maynard]]
*[[Natick, Massachusetts|Natick]]
*[[North Reading, Massachusetts|North Reading]]
*[[Pepperell, Massachusetts|Pepperell]]
*[[Reading, Massachusetts|Reading]]
*[[Sherborn, Massachusetts|Sherborn]]
*[[Shirley, Massachusetts|Shirley]]
*[[Stoneham, Massachusetts|Stoneham]]
*[[Stow, Massachusetts|Stow]]
*[[Sudbury, Massachusetts|Sudbury]]
*[[Tewksbury, Massachusetts|Tewksbury]]
*[[Townsend, Massachusetts|Townsend]]
*[[Tyngsborough, Massachusetts|Tyngsborough]]
*[[Wakefield, Massachusetts|Wakefield]]
*[[Wayland, Massachusetts|Wayland]]
*[[Westford, Massachusetts|Westford]]
*[[Weston, Massachusetts|Weston]]
*[[Wilmington, Massachusetts|Wilmington]]
*[[Winchester, Massachusetts|Winchester]]
{{div col end}}

===Census-designated places===
{{div col|colwidth=12em}}
*[[Ayer (CDP), Massachusetts|Ayer]]
*[[Cochituate, Massachusetts|Cochituate]]
*[[Devens, Massachusetts|Devens]]
*[[East Pepperell, Massachusetts|East Pepperell]]
*[[Groton (CDP), Massachusetts|Groton]]
*[[Hanscom AFB, Massachusetts|Hanscom AFB]]
*[[Hopkinton (CDP), Massachusetts|Hopkinton]]
*[[Hudson (CDP), Massachusetts|Hudson]]
*[[Littleton Common, Massachusetts|Littleton Common]]
*[[Pepperell (CDP), Massachusetts|Pepperell]]
*[[Pinehurst, Massachusetts|Pinehurst]]
*[[Shirley (CDP), Massachusetts|Shirley]]
*[[Townsend (CDP), Massachusetts|Townsend]]
*[[West Concord, Massachusetts|West Concord]]
{{div col end}}

===Other villages and neighborhoods===
{{div col|colwidth=12em}}
*[[Auburndale, Massachusetts|Auburndale]]
*[[Chestnut Hill, Massachusetts|Chestnut Hill]]
*[[East Lexington, Massachusetts|East Lexington]]
*[[Felchville, Massachusetts|Felchville]]
*[[Forge Village Historic District|Forge Village]]
*[[Gleasondale, Massachusetts|Gleasondale]]
*[[Graniteville Historic District (Westford, Massachusetts)|Graniteville]]
*[[Greenwood, Massachusetts|Greenwood]]
*[[Melrose Highlands, Massachusetts|Melrose Highlands]]
*[[Nabnasset, Massachusetts|Nabnasset]]
*[[Newton Centre, Massachusetts|Newton Centre]]
*[[Newton Highlands, Massachusetts|Newton Highlands]]
*[[Newton Lower Falls]]
*[[Newton Upper Falls]]
*[[Newtonville, Massachusetts|Newtonville]]
*[[Nonantum, Massachusetts|Nonantum]]
*[[North Billerica, Massachusetts|North Billerica]]
*[[North Chelmsford, Massachusetts|North Chelmsford]]
*[[North Woburn, Massachusetts|North Woburn]]
*[[Pingryville, Massachusetts|Pingryville]]
*[[Saxonville, Massachusetts|Saxonville]]
*[[Thompsonville, Massachusetts|Thompsonville]]
*[[Waban, Massachusetts|Waban]]
*[[West Newton, Massachusetts|West Newton]]
{{div col end}}

==Education==
{{expand section|date=July 2022}}
School districts include:<ref>{{cite web|url=https://www2.census.gov/geo/maps/DC2020/PL20/st25_ma/schooldistrict_maps/c25017_middlesex/DC20SD_C25017.pdf|title=2020 CENSUS - SCHOOL DISTRICT REFERENCE MAP: Middlesex County, MA|publisher=[[U.S. Census Bureau]]|accessdate=July 22, 2022|archive-date=July 22, 2022|archive-url=https://web.archive.org/web/20220722170353/https://www2.census.gov/geo/maps/DC2020/PL20/st25_ma/schooldistrict_maps/c25017_middlesex/DC20SD_C25017.pdf|url-status=live}} - [https://www2.census.gov/geo/maps/DC2020/PL20/st25_ma/schooldistrict_maps/c25017_middlesex/DC20SD_C25017_SD2MS.txt Text list] {{Webarchive|url=https://web.archive.org/web/20220722170353/https://www2.census.gov/geo/maps/DC2020/PL20/st25_ma/schooldistrict_maps/c25017_middlesex/DC20SD_C25017_SD2MS.txt |date=July 22, 2022 }}</ref>

K-12:

{{div col|colwidth=30em}}
* [[Ayer-Shirley School District]]
* [[Acton-Boxborough Regional School District]]
* [[Arlington School District (Massachusetts)|Arlington School District]]
* [[Ashland School District (Massachusetts)|Ashland School District]]
* [[Bedford School District]]
* [[Belmont School District]]
* [[Billerica School District]]
* [[Burlington School District (Massachusetts)|Burlington School District]]
* [[Cambridge Public School District]]
* [[Chelmsford School District]]
* [[Dracut School District]]
* [[Everett School District (Massachusetts)|Everett School District]]
* [[Framingham School District]]
* [[Groton-Dunstable School District]]
* [[Holliston School District]]
* [[Hopkinton School District]]
* [[Hudson School District]]
* [[Lexington School District]]
* [[Littleton School District]]
* [[Lowell Public Schools]]
* [[Malden School District]]
* [[Marlborough School District]]
* [[Maynard School District (Massachusetts)|Maynard School District]]
* [[Medford Public Schools]]
* [[Melrose School District]]
* [[Nashoba Regional School District]]
* [[Natick School District]]
* [[Newton School District]]
* [[North Middlesex School District]]
* [[North Reading School District]]
* [[Reading Public Schools]]
* [[Somerville School District]]
* [[Stoneham School District]]
* [[Tewksbury School District]]
* [[Tyngsborough School District]]
* [[Wakefield School District]]
* [[Waltham School District]]
* [[Watertown School District]]
* [[Wayland School District]]
* [[Westford School District]]
* [[Weston School District]]
* [[Wilmington School District]]
* [[Winchester School District]]
* [[Woburn School District]]
{{div col end}}

Secondary:
* [[Concord-Carlisle School District]]
* [[Dover-Sherborn School District]]
* [[Lincoln-Sudbury School District]]

Elementary:
{{div col|colwidth=30em}}
* [[Carlisle School District (Massachusetts)|Carlisle School District]]
* [[Concord School District (Massachusetts)|Concord School District]]
* [[Lincoln School District (Massachusetts)|Lincoln School District]]
* [[Sherborn School District]]
* [[Sudbury School District]]
{{div col end}}

Tertiary institutions include:
* [[Harvard University]] (Cambridge)
* [[Massachusetts Institute of Technology]] (MIT) (Cambridge)
* [[Tufts University]]  (Medford & Somerville)
* [[University of Massachusetts Lowell]] (Lowell)
* [[Framingham State University]] (Framingham)
* [[Middlesex Community College (Massachusetts)]] (Lowell & Bedford)

==Culture==
Middlesex County is home to the [[Middlesex County Volunteers]], a fife and drum corps that plays music from the 17th, 18th, 19th and 20th centuries. Founded in 1982 at the end of the United States Bicentennial celebration, the group performs extensively throughout New England. They have also performed at the Boston Pops, throughout the British Isles and Western Europe, and at the Edinburgh Military Tattoo's Salute to Australia in Sydney, Australia.

==See also==
{{portal|Massachusetts}}
* [[Middlesex]], historic county of England
* [[List of Massachusetts locations by per capita income]]
* [[Registry of Deeds (Massachusetts)#Middlesex|Registry of Deeds (Massachusetts)]]
* [[National Register of Historic Places listings in Middlesex County, Massachusetts]]
* [[Middlesex Fells Reservation|Middlesex Fells]]
* [[Middlesex Turnpike (Massachusetts)]]
* [[Middlesex County Sheriff's Office]]

== Explanatory notes ==
{{Notelist}}

==References==

{{reflist}}

===Bibliography===
* [https://archive.org/details/bub_gb_QGolOAyd9RMC <!-- quote=intitle:History intitle:of intitle:Middlesex intitle:County intitle:Massachusetts. --> History of Middlesex County, Massachusetts, Volume 1 (A-H)], [https://archive.org/details/historymiddlese00drakgoog/page/n314 <!-- pg=506 quote=intitle:History intitle:of intitle:Middlesex intitle:County intitle:Massachusetts. --> Volume 2 (L-W)] by Samuel Adams Drake, published 1879 and 1880. 572 and 505 pages.
* [https://archive.org/details/ancientmiddlese00goulgoog <!-- quote=Ancient Middlesex. --> ''Ancient Middlesex with Brief Biographical Sketches''.] By Levi Swanton Gould, published 1905, 366 pages.

==Further reading==
* {{Cite book |publisher = At the presses of S. Hall, and Thomas & Andrews |location = Boston, Massachusetts |author = Jedidiah Morse |author-link=Jedidiah Morse |title = The American Gazetteer |chapter-url=https://archive.org/stream/americangazettee00mors#page/n329/mode/2up |chapter=Middlesex |date = 1797 |ol = 23272543M }}
* Edwin P. Conklin, ''Middlesex County and Its People: A History.'' In Four Volumes. New York: Lewis Historical Pub. Co., 1927.
* Samuel Adams Drake,  ''History of Middlesex County, Massachusetts: Containing Carefully Prepared Histories of Every City and Town in the County.'' Boston: Estes and Lauriat, 1880. <small>[https://archive.org/details/historymiddlese01drakgoog Volume 1] | [https://archive.org/details/historymiddlese00drakgoog Volume 2]</small>
* D. Hamilton Hurd, ''History of Middlesex County, Massachusetts: With Biographical Sketches of Many of its Pioneers and Prominent Men.'' In Three Volumes. Philadelphia, PA: J.W. Lewis & Co., 1890. <small>[https://archive.org/details/middlesexcounty01hurd Volume 1] | [https://archive.org/details/historyofmiddles00hurd2 Volume 2] | [https://archive.org/details/historyofmiddles00hurd3 Volume 3]</small>
* Robert H. Rodgers, ''Middlesex County in the Colony of the Massachusetts Bay in New England: Records of Probate and Administration, February 1670/71 – June 1676.'' Rockport, ME: Picton Press, 2005.

==External links==
{{Commons category}}
* [http://www.middlesexsheriff.org/ Middlesex County Sheriff's Department]
* [https://www2.census.gov/geo/maps/general_ref/cousub_outline/cen2k_pgsz/ma_cosub.pdf US Census Bureau map] of cities, towns, Native American reservations, and census-designated places
* [https://archive.today/20130414114347/http://maps.bpl.org/details_12690 1856 Map of Middlesex County] by Henry F. Walling
* Walling & Gray. [https://web.archive.org/web/20080404034546/http://www.salemdeeds.com/atlases_pages.asp?ImageName=PAGE_0044_0045.jpg&atlastype=MassWorld&atlastown=&atlas=MASSACHUSETTS+1871&atlas_desc=MASSACHUSETTS+1871&pageprefix= 1871 Map of Middlesex County Plate 44-45] from the [https://web.archive.org/web/20080404033909/http://www.salemdeeds.com/atlases_results.asp?ImageType=index&atlastype=MassWorld&atlastown=&atlas=MASSACHUSETTS+1871&atlas_desc=MASSACHUSETTS+1871 1871 Atlas of Massachusetts.]
* [http://www.nationalregisterofhistoricplaces.com/MA/Middlesex/districts.html National Register of Historic Places listing for Middlesex Co., Massachusetts]
* [http://newenglandtowns.org/massachusetts/middlesex-county Middlesex County entry from Hayward's New England Gazetteer of 1839]
* [http://www.sec.state.ma.us/cis/cispdf/ma_city_town.pdf Map of cities and towns of Massachusetts] {{Webarchive|url=https://web.archive.org/web/20110927054352/http://www.sec.state.ma.us/cis/cispdf/ma_city_town.pdf |date=September 27, 2011 }}
* [http://www.sec.state.ma.us/cis/cispdf/ma_counties.pdf Massachusetts County Map]
* [https://archive.org/details/historymiddlese00drakgoog/page/n164 <!-- pg=158 --> History of Middlesex County] by Samual Adams Drake, 1880. Contains the histories of each town in the county.
* [https://books.google.com/books?id=m74TAAAAYAAJ History of Middlesex County, Massachusetts With Biographical Sketches of Many of Its Pioneers and Prominent Men], edited by Duane Hamilton Hurd. J. W. Lewis & Co., Philadelphia. 1890.
* [http://www.lowelldeeds.com/ Middlesex North District Registry of Deeds]
* [https://www.masslandrecords.com/ Middlesex South District Registry of Deeds]
* [https://web.archive.org/web/20040421135513/http://lwvma.org/govcounty.shtml League of Women Voters, Massachusetts: County Government]

{{Geographic Location
|Centre    = Middlesex County, Massachusetts
|North     = [[Hillsborough County, New Hampshire]]
|Northeast = [[Essex County, Massachusetts|Essex County]]
|East      =
|Southeast = [[Suffolk County, Massachusetts|Suffolk County]]
|South     = [[Norfolk County, Massachusetts|Norfolk County]]
|Southwest =
|West      = [[Worcester County, Massachusetts|Worcester County]]
|Northwest =
}}
{{Middlesex County, Massachusetts}}
{{Massachusetts}}
{{Greater_Boston}}
{{Massachusetts Public High Schools}}
{{Authority control}}

[[Category:Middlesex County, Massachusetts| ]]
[[Category:Massachusetts counties]]
[[Category:Counties in Greater Boston]]
[[Category:1643 establishments in the Massachusetts Bay Colony]]
[[Category:Populated places established in 1643]]
[[Category:1997 disestablishments in Massachusetts]]
[[Category:Populated places disestablished in 1997]]