SGA may refer to:
- Old Irish language (ISO 639-3 code)
- Schwarz-Gelbe Allianz (Black-Yellow Alliance), an Austrian political party
- Second-generation antipsychotics
- Séminaire de Géométrie Algébrique du Bois Marie, an influential mathematical seminar and the series of books it produced.
- SGA Airlines (Siam General Aviation), a regional airline in Thailand
- SG&A, Selling, General and Administrative expenses in income statements
- Simple Genetic Algorithm
- Small for gestational age, babies whose birth weight lies below the 10th percentile for that gestational age
- Society of Graphic Art, a British arts organization founded in 1919
- Songwriters Guild of America, an organization to help "advance, promote, and benefit" the profession of songwriters
- Southern Governors' Association
- Standard Galactic Alphabet, the writing system in the Commander Keen fictional universe
- Stargate Atlantis, an American-Canadian science fiction television series and a spin-off from the television series Stargate SG-1
- Student Government Association, a student organization dedicated to social and organizational activities of the student body
- Substantial gainful activity, a term defined by the U.S. Social Security Administration to describe work that involves physical or mental effort and is ordinarily done for pay
- Swanson Group Aviation, Formerly Superior Helicopter of Glendale, Oregon, a heavy lift helicopter operator
- Swedish Game Awards, Sweden's largest video game development competition
- Synthetic genetic array analysis - a high throughput methodology for studying genetic interactions
- System Global Area, a shared memory structure that is created by Oracle databases at instance startup
- Samsung Galaxy Ace, an Android smartphone manufactured by Samsung
- Segesterone acetate, a progestin medication
- Shai Gilgeous-Alexander, Canadian professional basketball player