SRF
- .srf
- Resonance
- SENS Research Foundation
- SRF Limited
- Scholar Rescue Fund
- Schweizer Radio und Fernsehen
- Self-Realization Fellowship
- Serum response factor
- Server Response File
- Sevin Rosen Funds
- Silk Road Fund
- SleepResearch Facility
- Solid recovered fuel
- Spec Racer Ford
- State revolving fund
- Strategic Rocket Forces
- Sudan Revolutionary Front
- Supercentenarian Research Foundation
- Superconducting radio frequency
- Syria Revolutionaries Front
- Systematic reconnaissance flight