| FSL | Failure to Stop for a Light 
| Others |
| FSL | Faith Service Life
| Others |
| FSL | Family Service League
| Others |
| FSL | Fast Simplex Link
| Others |
| FSL | Federal State and Local
| Others |
| FSL | Fictional Senshi Library
| Others |
| FSL | Fidelity Security Life
| Others |
| FSL | Field Service Logistics
| Others |
| FSL | Field Stocking Location
| Others |
| FSL | Fielder in Square Leg
| Others |
| FSL | Filipino Sign Language
| Others |
| FSL | Fire Services Levy
| Others |
| FSL | First Set Last
| Others |
| FSL | First Ship Lease
| Others |
| FSL | Firstsource Solutions Ltd
| Others |
| FSL | Fix Silvia Later
| Others |
| FSL | Fixed Spread Loans
| Others |
| FSL | Flight Simulation Laboratory
| Others |
| FSL | Flight Systems Laboratory
| Others |
| FSL | Florida State League
| Others |
| FSL | Fluid Science Laboratory
| Others |
| FSL | FMRIB Software Library
| Others |
| FSL | Folded Stopper Layer
| Others |
| FSL | Folk Singers Log
| Others |
| FSL | Food, Security, and Livelihood
| Others |
| FSL | Forecast Systems Laboratory
| Others |
| FSL | Forensic Science Laboratory
| Others |
| FSL | Form (Paradox for Windows)
| Others |
| FSL | Formal Systems Laboratory
| Others |
| FSL | Forward Short Leg
| Others |
| FSL | Forward Stocking Location
| Others |
| FSL | Fossil Downs, Western Australia, Australia
| Others |
| FSL | Foundation for Senior Living
| Others |
| FSL | Foundations For Safety Leadership
| Others |
| FSL | Foundstone Scripting Language
| Others |
| FSL | Fraternity and Sorority Life
| Others |
| FSL | Fraternity Sorority Life
| Others |
| FSL | Free Space Loss
| Others |
| FSL | Free Standing Lace
| Others |
| FSL | Freescale Semiconductor Ltd
| Others |
| FSL | Freestar Sel
| Others |
| FSL | French as a Second Language
| Others |
| FSL | French Sign Language
| Others |
| FSL | Fresnel Selector Language
| Others |
| FSL | Friendly Secure Lovable
| Others |
| FSL | Front Cover Seal
| Others |
| FSL | Front Side Left
| Others |
| FSL | Fuel Systems Lab
| Others |
| FSL | Full Schedule League
| Others |
| FSL | Full Supply Level
| Others |
| FSL | Fulton Supercomputing Lab
| Others |
| FSL | Furniture Symbol Library
| Others |
| FSL | Future School Leaders
| Others |