GSI
GSI stands for:
- Geological Society of India
- Geological Survey of India
- GSI Helmholtz Center for Heavy Ion Research , formerly: Society for Heavy Ion Research
- Geschwister-Scholl-Institute for Political Science
- Switzerland-Israel society
- GSI - Special Unit Gothenburg (Johan Falk - Gruppen för särskilda Insatser) , a Swedish crime series
- Gesellschaft für Schweißtechnik International mbH, umbrella organization for welding technology research in Germany
- Grand Sport Injection , a name analogous to Gran Turismo Injection for sporty model variants from Opel
- Grid Security Infrastructure , a security framework for grid computing
- The Gustav Stresemann Institute , an educational and conference center in Bonn
- Global Solutions Initiative , think tanks in the context of the G20 process
- GSI (file format) , for measuring instruments from Leica Geosystems
- GSI Commerce