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)