FFS
FFS may refer to:

Computing
Feige–Fiat–Shamir identification scheme, in cryptography
Flash file system
Formatted File System
Find first set, a type of bit operation
FreeFileSync, a software package
Amiga Fast File System
Berkeley Fast File System

Music
FFS (band), a rock supergroup of Franz Ferdinand and Sparks
FFS (album), their debut album

Organizations
Political organizations
For our Future’s Sake, a UK campaign group calling for a public vote (People's Vote) on the final Brexit deal
Social Forces Front (French: Front des Forces Sociales), a political party in Burkina Faso
Socialist Forces Front (French: Front des Forces socialistes), a political party in Algeria

Other organizations
Frankford Friends School, in Philadelphia, Pennsylvania, United States
French Federation of Speleology
Swiss Federal Railways (Italian: Ferrovie federali svizzere)

Places
FFS Arena, in Lund, Sweden
Frankfurt South station, in Germany
French Frigate Shoals, an island in the Northwestern Hawaiian Islands

Science and technology
Facial feminization surgery
Free-fall sensor
Fringe field switching
Full flight simulator

Other uses
Farmer Field School, a community development process
Fee-for-service, a payment model
For Film's Sake, Australian women's film festival
Fully fashioned stockings, stockings with reinforce toe and tops