| Acronym | Definition |
|---|
| FSS | Forum for Social Studies (Ethiopian aid) |
| FSS | Full Service Supplier |
| FSS | Force Support Squadron |
| FSS | Fonds des Services de Santé (French: Contribution to the health services fund; Québec, Canada) |
| FSS | Fine Sun Sensor |
| FSS | Functional Somatic Syndrome (disease group) |
| FSS | Field Service Specialist |
| FSS | Financial Service Standards LLC |
| FSS | Fast System Switch (Unix) |
| FSS | Flight Support Structure |
| FSS | Fuel Supply System |
| FSS | Fonds Spécial de Solidarité (French: Belgium insurance) |
| FSS | Fixed Service System |
| FSS | Familial Short Stature |
| FSS | Federal Supply Schedule/Service |
| FSS | Frontenac Secondary School (Ontario, Canada) |
| FSS | Frequency-Selective Structure |
| FSS | Facility Status Sheet |
| FSS | Fokker Space Systems |
| FSS | Feng Shui Society (UK) |
| FSS | Family Support Services of North Florida, Inc. |
| FSS | Facilities Security and Safeguards Division |
| FSS | Food Service Sergeant |
| FSS | Full-Scale Simulator |
| FSS | Frequency Surveillance System |
| FSS | Forward Supply Support |
| FSS | Flutter Suppression System |
| FSS | Fuel Supply Shutdown |
| FSS | Fully Separate Subsidiary |
| FSS | Flight Software Subsystem |
| FSS | Functional Simulation System |
| FSS | Fire Support Status |
| FSS | Flexibles Service System |
| FSS | Facility Service Selective |
| FSS | Fade-Slope Statistic(s) |
| FSS | Forward Scatter System |
| FSS | Fault Status Symbol |
| FSS | Failed Signal State |
| FSS | Forward Support Site |
| FSS | Forward Scatter Site |
| FSS | Flight Security Supervisor |
| FSS | Fixed Site SCAMP |
| FSS | Fast Slot Synchronization |
| FSS | Fire Survey System (insurance) |
| FSS | Facility Support Subsystem |
| FSS | Fiber Sequence Selection |
| FSS | Frequent State Saving |
| FSS | Full Supply Support |
| FSS | Firefinder Survivability Suite |
| FSS | File Survey System |
| FSS | Fin Stabilizer System |
| FSS | Financial Shared Services |
| FSS | Fire Support Section |
| FSS | Fire Support Station |
| FSS | Family Self-Sufficiency |
| FSS | Fast Sealift Ship |
| FSS | Field Service Site |
| FSS | Field Support Services |
| FSS | Fixed Sample Size |
| FSS | Fixed Satellite Service |
| FSS | Flight Service Station |
| FSS | Forensic Science Society |
| FSS | Frequency Selective Surface |
| FSS | Fire Support System |
| FSS | Forensic Science Service (Great Britain) |
| FSS | Fire Suppression System |
| FSS | Facility Support Services (various locations) |
| FSS | Fellow of the Statistical Society |
| FSS | Financial Services Specialist |
| FSS | Friday, Saturday, Sunday (movie weekend box office receipts) |
| FSS | Financial System Stability |
| FSS | Fall Symposium Series (Association for the Advancement of Artificial Intelligence) |
| FSS | File Sharing Services |
| FSS | Financial Supervisory Service (South Korea) |
| FSS | Fanguard Security Services (UK) |
| FSS | Flow State Scale |
| FSS | Force Sustainment Systems |
| FSS | First Stop Shop |
| FSS | Federal Security Service |
| FSS | Fakulta Socialnich Studii (Czech: Faculty of Social Studies) |
| FSS | Flight Support System |
| FSS | Flight Service Specialist (US FAA) |
| FSS | Food Service Solutions (Altoona, PA) |
| FSS | Family Stabilization Service (various locations) |
| FSS | Freeman-Sheldon Syndrome |
| FSS | Food Safety Summit (exhibition) |
| FSS | Fail-Safe State |
| FSS | Flinders Street Station ( Melbourne, Australia) |
| FSS | Fyshwick Self Storage (Australia) |
| FSS | Faculty Salary Survey |
| FSS | Flats Sequencing System (USPS) |
| FSS | Flight Safety System |
| FSS | Foundation Stock Service |
| FSS | Fire Safety System |
| FSS | Federal Supply Service (US General Services Administration) |
| FSS | Fellow of the Royal Statistical Society (UK; also seen as FRSS; aka Fellow of the Statistical Society) |
| FSS | Flextronics Software Systems (India) |