HAC

HAC may refer to:

Arts

 * Harrow Arts Centre, London, England
 * Humboldt Arts Council

Conventions

 * Hague Adoption Convention, a 1993 international treaty on protection of children and co-operation in respect of intercountry adoption
 * High Ambition Coalition, an informal group of approximately 61 countries within the UN Framework Convention on Climate Change (UNFCCC)

Government

 * Hakka Affairs Council, of the Republic of China
 * House Appropriations Committee, a committee of the United States House of Representatives

Organisations

 * Hadassah Academic College, Jerusalem, Israel
 * Hague Academic Coalition
 * Honourable Artillery Company, a British Army unit and a charitable organisation
 * Higher Attestation Commission, a national government agency in Russia, Ukraine and some other post-Soviet states that oversees awarding of advanced academic degrees
 * Humanist Association of Canada
 * Sudan Humanitarian Aid Commission
 * H.A.C. Inc., parent company of the Homeland chain of supermarkets in the U.S. state of Oklahoma.

Science and engineering

 * Acetic acid (HAc)
 * High acid crude oil, a crude oil with a high concentration of naphthenic acids
 * High Alumina Cement (HAC), now known generally as Calcium aluminate cements
 * Human artificial chromosome
 * Newey–West HAC estimator
 * Hierarchical agglomerative clustering, a type of hierarchical clustering
 * Lucile Hac (1909–2006), American biochemist and microbiologist

Sport

 * Hoosier Athletic Conference
 * Hóquei Académico de Cambra, a Portuguese rink hockey club
 * Le Havre Athletic Club, a French football club
 * Horoya AC, a Guinean football club
 * Hydra AC, an Algerian football club

Transport

 * Hachijojima Airport, in the Izu Islands, Japan
 * Hackney Downs railway station, in London
 * Hokkaido Air System
 * Hrvatske autoceste, a Croatian motorway operator
 * Hughes Aircraft Company

Other uses

 * Gorani language (ISO 639-3: hac)
 * Hectare
 * High-availability cluster
 * Honorary Air Commodore
 * Hospital-acquired condition
 * Hot Action Cop, an American band
 * Hot adult contemporary, a radio format
 * Hyles–Anderson College
 * HAC, a product code prefix used for the Nintendo Switch, its software, and accessories