GAC
- GAC
- GAC Group
- GAC Ireland
- GAK (disambiguation)
- Gach
- Gack
- Games Administration Committee
- Gateway Athletic Conference
- Gać (disambiguation)
- Gender affirming care
- General Amusement Corporation
- Geological Association of Canada
- Ghost Adventures Crew
- Global Action for Children
- Global Affairs Canada
- Global Assembly Cache
- Global Assessment Certificate
- Globular Amphora culture
- Gloster Aircraft Company
- Graphic Adventure Creator
- Great American Conference
- Great American Family
- Grumman Aerospace Corporation
- Guglielmo Achille Cavellini
- Gulfstream Aerospace Corporation
- Gấc
- Lagos State Government
- Le Gac
- Mindpixel
- Nigeria