GG may refer to:
- Gg: Gigagram, grams
- Grundgesetz, the German constitution, abbreviation in German legal use
- Air Comores International, under the IATA airline designations
- Kenkyūsha's New Japanese-English Dictionary (affectionately called "Green Goddess" or "GG" for short)
- Genetic girl (synonym nf, meaning natal female), used in contrast to a male-to-female transsexual
In Networking:
- .gg, the Top-Level Domain country code for Guernsey
- Gadu-Gadu, an instant messaging program popular in Poland
In Gaming:
- Good game, internet slang that may be used at the end of a close game or match as a sign of competitive or generally good sportsmanship (the opposite of bad game)
- GameGuard, a hacking protection program used in some MMORPGs
- Gg (pronounced "geg"), an alien race from the Star Control series of video games
- Guilty Gear (series)
In Companies and organizations:
- Goldcorp, a New York stock exchange listed company, symbol GG
In Music:
- G. G. (album), Gary Glitter's third studio album, released in 1975
- Girls' Generation, Korean girl group