GNS may refer to:
- Gandhi National School, Ancol, a school in Jakarta, Indonesia
- Gelfand–Naimark–Segal construction, a theorem in algebra
- General News Service, a BBC-internal news distribution service
- GEOnet Names Server, a database of place names and locations
- Gesellschaft für Nuklear Service, a German nuclear waste services company.
- Glenlyon Norfolk School, an independent university preparatory school in Victoria, BC, Canada
- GNS Science, a New Zealand earth science research institute
- GNS Theory, a theory of roleplaying gamers and game design
- Gordon-North Sydney Hockey Club a field hockey club based in Sydney, Australia
- Government of National Salvation, a World War II Serbian puppet government
- Grain neutral spirit, a liquid distilled from cereal grain