APA

APA may stand for:
* American Psychiatric Association
* American Psychological Association; also
** APA style, a writing format developed by the above
* American Psychoanalytic Association
* American Psychopathological Association

APA may also stand for:
* Acolytes Protection Agency, a former professional wrestling tag-team
* Adirondack Park Agency
* Administrative Procedure Act, an American statute controlling government agency actions
* Advance Pricing Agreement
* Affine projection algorithm
* Allied Pilots Association
* All Points Addressable
* Amateur Press Association
* American Pale Ale
* American Payroll Association
* American Philological Association
* American Philosophical Association
* American Planning Association
* American Polygraph Association
* American Poolplayers Association
* American Poultry Association
* American Protective Association, an American anti-Catholic organization during the Gilded Age
* Americanist Phonetic Alphabet
* Anglican Province of America
* Antagonist Perpetrated Aggression, a Special Tactics Close Quarters Combat Sysytem
* Anti-pedophile activism
* Apache Railway, from its Association of American Railroads reporting mark
* ARCAM Private Army
* Army Prosecuting Authority
* Asia and the Pacific, UNESCO region
* Asian Pacific American
* Association of Publishing Agencies
* Australian Physiotherapy Association
* Australian Postgraduate Awards
* Australian Progressive Alliance
* Austrian Press Agency
* Azeri Press Agency
* Centennial Airport, Arapahoe County, Colorado, United States, from its IATA airport code
* Hong Kong Academy for Performing Arts
* Japan Advertising Photographers' Association
* Southern Athabaskan languages (excluding Navajo), from their ISO 639 code

Apa (without caps) may refer to:
*Apa, Nigeria, a Local Government Area in Benue State, Nigeria
*Apa, Satu Mare, a commune in Satu Mare County, Romania
**a type of sword named after the village; see Bronze Age sword
*Appa, a Nepali Sherpa and famous Mt. Everest mountaineer