GCA may refer to:
Education Cayman Islands Grace Christian Academy (Cayman Islands)
India Government College, Ajmer, Rajasthan Guwahati College of Architecture, in Assam
United Kingdom Greig City Academy, in London
United States Gahanna Christian Academy, in Columbus, Ohio Garland Christian Academy, in Garland, Texas Georgia-Cumberland Academy, in Calhoun, Georgia Global Communications Academy, in Hartford, Connecticut Granville Christian Academy, in Granville, Ohio Greenbrier Christian Academy, in Chesapeake, Virginia
Science and mathematics GCA (gene) Generalized Clifford algebra Geochimica et Cosmochimica Acta, a scientific journal Giant-cell arteritis GCA, a codon for the amino acid alanine
Sport Geelong Cricket Association, in Australia Goa Cricket Association, in India Gujarat Cricket Association, in India
Other uses Garden Centers of America, an American trade organization GCA Airlines, a Colombia airline GCA Games Convention Asia, a video game and interactive technology convention GCA Savvian, an American investment bank Giant cell arteritis, a disorder Global Center on Adaptation, an international organization aiming to accelerate climate change adaptation solutions Goodreads Choice Awards, book awards Gothenburg City Airport, in Sweden Grand Canyon Association, an American fundraising organization Grand Central Airport (United States), a former airport in Glendale, California, United States Grand China Air, a Chinese airline The Great Canadian Appathon, a Canadian game design and development competition Great Commission Association, an association of evangelical Christian churches Greek Cypriot Administration of Southern Cyprus, a name used for the internationally recognized Republic of Cyprus by Turkey since they do not recognize it The Greeting Card Association, a British trade organization Ground-controlled approach Groceries Code Adjudicator, in the United Kingdom Gun Control Act of 1968, a U.S. federal law Gun Control Australia, an Australian lobbying group Greater Central Asia, a region of Eurasia