| Acronym | Definition |
|---|
| ISF | Impôt de Solidarité sur la Fortune (French: wealth tax) |
| ISF | International Softball Federation |
| ISF | Imaging Science Foundation |
| ISF | Iraqi Security Force |
| ISF | International Seed Federation (Switzerland) |
| ISF | International Shipping Federation |
| ISF | Importer Security Filing |
| ISF | International Science Foundation |
| ISF | Insufficient Funds |
| ISF | Institute for Sustainable Futures (Sydney, Australia) |
| ISF | Insofar |
| ISF | Interstitial Fluid |
| ISF | Information Systems Frontiers |
| ISF | International Ski Federation |
| ISF | International Sepsis Forum |
| ISF | Integrated Social Forestry (Philippines) |
| ISF | I Sådana Fall |
| ISF | Ingenieros Sin Fronteras (Spanish: Engineers Without Borders) |
| ISF | Iowa State Fair |
| ISF | International Snowboarding Federation |
| ISF | International Shinto Foundation |
| ISF | Information Security Foundation |
| ISF | Islamic Salvation Front |
| ISF | Information Strike Force (Navy/Marine Corp Intranet; NMCI) |
| ISF | Industrial Space Facility |
| ISF | Integrative Strategies Forum |
| ISF | Integrated Support Facility |
| ISF | International School Frankfurt |
| ISF | Ingénierie Sans Frontières (French: Engineering Withouth Borders; Sherbrooke, Québec, Canada) |
| ISF | Ingénierie Sans Frontières (Engineers Without Borders) |
| ISF | Investigator Site File |
| ISF | Imperial Special Forces (gaming) |
| ISF | Integration Support Facility |
| ISF | Institute of Soil Fertility (Netherlands) |
| ISF | Infrastructure Support Facilities |
| ISF | Import Service Fee |
| ISF | Investigative Support & Forensics |
| ISF | International Society of Financiers, Inc. |
| ISF | In Service Failure |
| ISF | Intelligence Support Facility |
| ISF | Integrated Support-Fielding |
| ISF | Income Stabilization Fund |