ACA may refer to:

• A Current Affair (Australian TV series), an Australian television program
• Actors Centre Australia, a private dramatic arts school
• American Choreography Awards
• American Composers Alliance
• American Council for the Arts, now part of Americans for the Arts
• American Country Awards

• Advisory Committee for Aeronautics
• Aero Club of America, US aviation group, now the National Aeronautic Association
• Agile Combat Aircraft, forerunner to the British Aerospace EAP technology demonstrator aircraft
• Air Canada, by ICAO airline designator
• Arctic Control Area, a Canadian airspace region
• Astronautics Corporation of America
• Atlantic Coast Airlines, later Independence Air
• Austrian Cockpit Association, professional pilot organization
• IATA airport code for Acapulco International Airport in State of Guerrero, Mexico

• Alerting Communicators of America, an earlier name of American Signal Corporation
• Angel Capital Association
• Australian Coal Association

• Affordable Care Act, shorthand for the Patient Protection and Affordable Care Act, commonly called "Obamacare"
• Allied Commission for Austria
• Anti-Corruption Agency, a Malaysian government agency
• Australian Coal Association
• Australian Communications Authority

Historical

• Army Comrades Association, or "Blueshirts", a political organization in 1930s Ireland
• Armed Peasant Association (Spanish: Asociación Campesina Armada), also known as Armed Campesino Group, a Marxist–Leninist Paraguayan rebel group

• Academic Cooperation Association, international body to promote cooperation in higher education, based in Brussels
• Adult Children of Alcoholics, counseling and support group
• African Cashew Alliance, international organization for promoting Africa's cashew industry
• American Cadet Alliance, former non-government group for military cadet activities
• American Chess Association, chess organization founded in 1857 and dissolved a few years later
• American Citizens Abroad, non-profit group advocating for American expatriates
• American Cryptogram Association, group for cryptographic puzzles
• American Crystallographic Association, scientific society
• Amputee Coalition of America, advocacy and support group
• Analytica Chimica Acta, scientific journal
• Anti-Communist Action, a far-right organization
  • NSC-131, a neo-Nazi group
• Anglican Church in America, traditionalist Anglican church body
• Army Comrades Association ("Blueshirts"), Irish militant right-wing group in 1932-1933
• Association of Canadian Archivists, professional group for Canadian historical archivists
• Atheist Community of Austin, Texas non-profit group which produces The Atheist Experience TV program
• Automóvil Club Argentino, Argentina's largest automobile association
• Automobile Club of America

• ACA International, formerly the American Collectors Association
• American Callers Association, association of square dance callers
• American Camp Association, professional and trade association for summer (and similar) camp owners and workers
• American Chiropractic Association, professional association
• Australian Counselling Association, professional association
• American Counseling Association, professional association
• American Correctional Association, professional and trade association for prisons and prison officials and employees
• Australasian Corrosion Association, Australia and New Zealand trade association
• American College of Apothecaries, professional and trade association for independent community pharmacists

• Academic Cooperation Association, international group promoting cooperation in higher education, based in Brussels

• 7-ACA, 7-aminocephalosporanic acid
• Azodicarbonamide, a chemical foaming agent
• ACA, a codon for the amino acid threonine
• Anterior cerebral artery
• Anti-cardiolipin antibodies
• Anti-centromere antibodies
• Acrodermatitis chronica atrophicans
• ACA₀, an axiom system in reverse mathematics
• All common ancestors (ACA) point, also known as the identical ancestors point

• Adventure Cycling Association
• African Cricket Association
• American Canoe Association
• Argentine Cricket Association
• Australian Cricketers' Association
• AC Ajaccio, a French professional football team
• AC Arles-Avignon, a French professional football team
• Absolute Championship Akhmat, a mixed martial arts, kickboxing and Brazilian jiu-jitsu promotion based in Russia

• Antioch–Pittsburg (Amtrak station), by station code, in Antioch-Pittsburg, California

• aca, the ISO 639 code for the Achawa language of Colombia
• ACA Neo Geo, a series of Neo Geo re-releases made by Hamster Corporation and SNK, derived from Arcade Archives.
• Arabic chat alphabet

• All pages with titles beginning with ACA
• All pages with titles beginning with Aca
• All pages with titles containing aca
• Aka (disambiguation)
• ACKA