HCA may refer to:
- Haryana Chess Association
- Hall-Carpenter Archives
- Hans Christian Andersen, Danish author and poet, most famous for his fairy tales
- HC Andersen (band), Finnish rock band
- Henry Cookson Adventures, Outfit run by Record breaking Polar Explorer Henry Cookson
- Healthcare Assistant, in the UK
- Heidelberg Center for American Studies
- Helsinki Citizens Assembly
- Hennepin Center for the Arts, a building in Minneapolis, Minnesota
- Heritage Christian Academy, the name of a number of Christian schools in North America
- Heritage Crafts Association, a UK charity that helps to preserve traditional hand crafts
- Heterocyclic amines, organic compounds that have been partly identified as carcinogens, found in meat cooked at very high temperatures
- Hexachloroacetone, a pesticide
- Hierarchical Clustering, a method of cluster analysis in statistics
- High content analysis, a laboratory microscopic technique
- High Court of Australia
- Hillcrest Christian Academy, an independent primary school in South Africa
- Hinsdale Center for the Arts
- Historical cost accounting
- Hockey Club Ajoie, a team in Switzerland
- Holloway Cut Advisor, a method of rating brilliant cut diamonds
- Holy Child Academy, a Catholic school in Pagadian City, Philippines
- Honey Care Africa, a Kenyan honey-distributing franchise.
- Homes and Communities Agency, a UK non-departmental public body
- Hospital Corporation of America the largest for profit hospital chain, Senator Bill Frist family's company
- Hopkins Consulting Agency, a student-run technology consulting company at The Johns Hopkins University
- Host Channel Adapter, in electronic communications
- Hot Cranking Amps, a measurement of the current provided by a car battery
- Hydroxycitric acid
- Hydroxycarbonate Apatite