GA, Ga, or ga may refer to:

• Garuda Indonesia (IATA airline code GA)
• General Assembly, a digital and technology training company
• General Atlantic, a private equity company
• General Atomics (formerly GA Technologies Inc.), a U.S. defense contractor
• General Automation, a former computer manufacturer
• Georgia Railroad and Banking Company (AAR mark)
• Greater Anglia, a UK train operating company

• Gamblers Anonymous, a support group for recovering gamblers
• Gazte Abertzaleak or Young Patriots, the youth organization of Eusko Alkartasuna
• General assembly (disambiguation)
  • United Nations General Assembly, the main deliberative organ of the United Nations
• Geographical Association, a UK organisation dedicated to the teaching of geography
• Geologists' Association, a UK organisation dedicated to the study of geology
• Geoscience Australia, an Australian organisation dedicated to geoscientific research
• Germantown Academy, an independent school in Fort Washington, United States
• Government Arsenal, an agency of the Philippine government under the Department of National Defence

• Ga language
• General American English, an accent of the Midwestern U.S.
• Irish language (ISO 639-1 code "ga")

• Ga (Indic), a glyph in the Brahmic family of script
• Ga (Javanese) (ꦒ), a letter in the Javanese script
• Ga (kana), in Japanese

• Ga District, Ghana, a former district of southern Ghana
• Gã State, a traditional state in southern Ghana headed by the Gã Mantse
• Ga-Rankuwa, a town in South Africa
• Gabon (ISO 3166-1 alpha-2 code)
• The Gambia (FIPS 10-4 country code)

• Goa, in India (ISO 3166-2 country subdivision code GA)
• Georgia (U.S. state) (postal abbreviation GA)

• General anaesthesia, administration of drugs to induce unconsciousness prior to surgery
• Geographic atrophy, an advanced form of age-related macular degeneration
• Gestational age (obstetrics), in pregnancy, the time since onset of last menstrual period
• Embryonic age or gestational age, the length of gestation since fertilization
• Gibberellin, a plant growth hormone
• Tabun (nerve agent) (NATO designation GA)

• .ga, the country code top-level domain for Gabon
• General availability, the final stage in the software development lifecycle
• Genetic algorithm, an optimization technique in computer science
• Google Analytics, a web analytics service provided by Google

• Gallium (symbol Ga), a chemical element
• General aviation, the category of civil aviation encompassing all non-scheduled aircraft flights
• Geometric algebra, a Clifford algebra used in a geometric context
• Gigaampere (GA), an SI unit of electric current equal to 1,000,000,000 (one billion) amps
• Gigaannum (Ga), a unit of time equal to 1,000,000,000 (one billion) years.
• Go Ahead, in a telecommunications device for the deaf

• Goal attack, a position in netball
• Goals against, a statistic in ice hockey and other sports

• GA Geijutsuka Art Design Class, an ongoing 2004 manga series by Satoko Kiyuzuki
• Gandhara or Ga, a basic note of the scale in Indian music, or Svara
• Ga people, an ethnic group of Ghana
• General of the Army, a military rank
• Global affairs, abbreviated GA, alternative term for International relations, the study of politics, economics and law on a global level
• Graduate assistant, a role in academia and in U.S. college sports