# FS

FS, fS or fs may refer to:

## Arts and entertainment

* FS (musician) (real name Fred Sargolini), American dubstep producer and DJ from New York
* FS Catalogue, a numbered list of all compositions by Carl Nielsen
* FS Film, a Finnish film distributor
* Flight simulator, a professional simulator of planes
** Flight simulation video game, a video game version of simulators
*** Microsoft Flight Simulator, an amateur flight simulator series
**** Microsoft Flight Simulator X (FSX), the 2006 edition
**** Microsoft Flight Simulator (2020 video game) (FS), the 2020 edition
* Fox Sports (United States), the sports programming division of Fox Corporation
** Fox Sports 1 (FS1)
** Fox Sports 2 (FS2)

## Businesses and organizations

* Fagoppositionens Sammenslutning, a Danish trade union federation
* FamilySearch, a genealogical organization and website
* Farmers' and Settlers' Association of New South Wales (F & S), Australia
* Fortune Systems, a defunct American computer manufacturer
* Frankfurt School of Finance & Management, a business school in Frankfurt, Germany
* FS Services, an agricultural supply cooperative, now Growmark
* Full Sail University, a university in Florida, US
* Future Shop, a defunct Canadian consumer electronics retailer

### Transportation

* Ferrocarril de Sóller, a railway on Majorca
* Ferrovie dello Stato, Italian state railways
** Trenitalia, its subsidiary for operating passenger rail transport
* First ScotRail, a British rail train operator
* ItAli Airlines (former IATA code: FS), a former Italian airline (2003-2011)
* Flyr (airline) (former IATA code: FS), a former Norwegian airline (2020-2023)

## Science and technology

* Feldspar, a group of silicate minerals
* Fin-stabilized projectile, such as the APFSDS or HEAT-FS
* Flank speed, a ship's true maximum speed
* Frameshift mutation, a genetic mutation
* Fujita scale (F-Scale), or Fujita-Pearson scale, a scale for rating tornado intensity
* Full scale, in electronics and signal processing, the maximum amplitude a system can present
* Marine flooding surface, a sharp contact between deep-water and shallow-water facies in sequence stratigraphy
* Sampling rate (symbol $f_{s}$), in communications theory
* Fourier series, a mathematical tool used for analyzing periodic functions

### Computing

* FS register, in X86fs computer architecture
* File Separator, a character in the C0 and C1 control codes
* File server, a form of disk storage
* File system, in computer science and database theory
* Flipnote Studio, a DSi animation software
* Forward secrecy, a property of cryptographic systems
* Fullscreen, a picture format in 4:3 aspect ratio, as opposed to widescreen
* IBM Future Systems project a failed IBM project to develop a computer line to replace System/360
* Feature structure, a set of attribute–value pairs

### Medicine

* Felty's syndrome, autoimmune disease, with rheumatoid arthritis, enlargement of the spleen and too few neutrophils in the blood
* Fibrin sealant, a type of surgical tissue adhesive used during surgery to control bleeding
* Flight Surgeon, a physician who is responsible for the medical evaluation, certification and treatment of aviation personnel
* Fractional shortening, of the heart
* Formularium Slovenicum, Slovenian addendum to the European Pharmacopoeia

### Physics

* Femtosecond (fs), an SI unit of time
* Siemens (unit) Femtosiemens, an SI unit of electric conductance
* Fine structure, in atomic physics

## Military

* Freight and supply ship (FS), a US Army classification for a type of cargo ship
* Fire support, artillery or close air support for combat operations
* Flight Sergeant, a non-commissioned officer in some air forces
* Flight Surgeon, physician primarily responsible for the medical evaluation, certification and treatment of aviation personnel
* French Ship (FS), a NATO prefix for ships of the French Navy

## Sport

* Free safety, one variation of the defensive back position in American football
* Free skating, the second part of a figure skating competition
* Formula Student, a student engineering competition held annually in the UK

## Other uses

* Federal Standard 595, a United States federal standard defining color shades
* Financial Secretary (Hong Kong)
* For Sale (disambiguation)
* Foundation Stage, term used for early childhood education in the UK
* Franco's Spain, Spain under the leadership of Francisco Franco
* French Southern Territories (FIPS PUB 10-4 territory code); excludes the Terre Adélie portion of Antarctica
* Full service (disambiguation)