GCA
GCA stands for:
- Gas Connect Austria GmbH, a gas pipeline operator
- GCA (base triplet) coding for the canonical amino acid alanine , see Genetic Code for understanding
- GCA Games Convention Asia
- Général de corps d'armée , rank of general corresponding to the German lieutenant general
- Geochimica et Cosmochimica Acta , scientific bi-weekly peer-reviewed journal by Elsevier
- Global Coalition for Africa
- Green Communities Association
- Ground Controlled Approach , a radar-controlled, ground-guided blind landing procedure in aviation
- Guacamayas Airport (IATA code), Guacamayas Airport ( Boyacá) , Departamento de Boyacá , Colombia
- Guatemala (car registration)
- Gun Control Alliance
- Gun Control Act 1968
