FRS
- East Frisian Low Saxon
- Facial recognition system
- Facility Registry System
- Family Radio Service
- Family Resources Survey
- Federal Reserve System
- Fellow of the Royal Society
- Ffestiniog Railway
- File Replication Service
- Filtered Rayleigh scattering
- Fire and Rescue Service
- Fisheries Research Services
- Fixed repeating schedule
- Flandre Air
- Fleet Replacement Squadron
- Forsinard railway station
- Forum of Social Republicans
- Forward recoil scattering
- Fragment separator
- Frame Relay
- Framingham Risk Score
- Franconia–Springfield station
- Free Record Shop
- Free radical scavenger
- Free radical substitution
- Freely redistributable software
- Frontier Regional School
- Full-rigged ship
- Functional requirement
- Förde Reederei Seetouristik
- Mundo Maya International Airport
- Saterland Frisian language
- Scion FR-S