HHI

HHI may refer to:

• Fraunhofer Institute for Telecommunications (also Fraunhofer Heinrich Hertz Institute), an organization of the Fraunhofer Society based in Berlin
• Hamburg International (ICAO code: HHI), an independent passenger airline based in Hamburg-Nord, Hamburg, Germany
• Henry Henderson Institute, an educational establishment in Blantyre, Malawi
• Herfindahl–Hirschman index, a measure of the size of firms in relation to the industry they are in
• Hildesheim Hauptbahnhof (DS100 code: HHI), the main railway station for the city of Hildesheim in Lower Saxony, Germany
• Hillcrest Heights Institute, a private school located in the barangay of San Francisco, Magalang, Pampanga
• Hoia Hoia language (ISO 639-3 code: hhi), a Papuan language of Papua New Guinea
• Hopewell Highway Infrastructure, the highway unit of Hong Kong-listed conglomerate Hopewell Holdings Ltd
• Hyundai Heavy Industries, the world's largest shipbuilding company
• Wheeler Army Airfield (IATA code: HHI), a United States Army post located on O'ahu