GSG may refer to:
Businesses German Sport Guns GmbH, a German firearms manufacturer
Government Government Statistician Group, a community of government statisticians in the UK GSG 9, a German counter-terrorism and special operations unit
Other organizations George Street gang, a Belizean street gang Global Scenario Group, an environmental research organization Global Strategy Group, an American public affairs and research firm Grampian Speleological Group, a caving organisation, based in Scotland Great Southern Grammar, a school in rural Western Australia
Other uses German Sign Language (ISO 639-3 language code) The Good Schools Guide, a British guide to schools Grand strategy game, a genre of board games and video games