Franco's Spain, Francisco Franco's leadership of Spain

FS numbers, symphonic musical compositions assigned by Dan Fog and Torben Schousboe to the works of the twentieth-century Danish composer Carl Nielsen

Flight Simulator, a simulator that tries to replicate the experience of flying for military personnel

File system, in computer science and database theory

French Ship, a NATO prefix for ships of the French Navy

Descent: FreeSpace — The Great War, a space combat simulation computer game

Financial statements, the records of a business' financial activities

Fourier series, a mathematical tool used for analyzing periodic functions

United States Forest Service, part of the United States Department of Agriculture

Full Sail Real World Education, a university in Florida dedicated to real world education in the entertainment industry

FS technology, a research project studied by IBM in the early 1970's aiming to develop a revolutionary line of computer products

Future Sight, a set in the card game Magic: the Gathering

File Separator, a character in the C0 control code set

The Legend of Zelda: Four Swords, a video game in the popular Legend of Zelda series

FS, fS, and fs are two-letter abbreviations and may refer to many things.

FamilySearch, a family history website for genealogy and family history research and networking

ForumStyles, a resource site for ZetaBoards

Flagship Studios, a computer game company

femtosiemens, an SI unit of electric conductance

Farm Sanctuary, an animal protection organization

Free Safety, one variation of the defensive back position in American football

<math>f_s</math>, symbol for the Nyquist rate

File server, a form of disk storage

femtosecond, an SI unit of time

Free skating, the second part of a figure skating competition

Flight Sergeant, a non-commissioned officer in some air forces

Full Surface Records, an American record label

Ferrovie dello Stato, the Italian railways

Servicios de Transportes Aéreos Fueguinos, IATA airline designator

Força Sindical, a Brazilian trade union

Ferrocarril de Sóller, a railway on Majorca

Fire Support, a military term

Fibrin sealant, type of surgical tissue adhesive used during surgery to control bleeding

FS Studios, an art studios/production company

Fullscreen, the picture format as opposed to widescreen

French Southern Territories: FIPS PUB 10-4 territory code (excluding the Terre Adélie portion of Antarctica)

Fin-stabilized projectiles, such as APFSDS or HEAT-FS (ammunition for tank guns)