Finland as an abbreviation for Suomi-Finland. Suomi is the Finnish-language name for Finland.

Science fiction, a literary genre

The San Francisco 49ers, a franchise in the NFL

San Francisco, California, a city with a population of more than 730,000, located on the West Coast of the United States.

The San Francisco Giants, a franchise in the MLB

Scuderia Ferrari, the racing division of the Ferrari automobile company

Street Fighter (series), a series of electronic fighting games by the company Capcom

Sinn Féin, an Irish political party.

Special forces, small, highly trained and specialised military units

Sofia, Bulgaria, the capital city of Bulgaria

Switchfoot, an alt-rock band

Salad Fingers, a flash animation created by David Firth

Six Flags, a chain of theme parks

The Hull classification symbol for a "Fleet Submarine" in the United States Navy

Significant figures (in mathematics)

Socialistisk Folkeparti, the Danish Socialist People's Party

SourceForts, a modification of the Half-Life 2 first-person shooter game

Steve Francis, an NBA player for the Houston Rockets

SF DRS, Schweizer Fernsehen (Swiss Television)

Shadows Fall, a metal band

An obscure alternative abbreviation for the Valley Girl slang term "As if!" (see Valspeak)

Scaterd Few, a Christian punk band

Senses Fail a hardcore punk band from New Jersey

Soldier Front, a tactical first-person shooter game, licensed by ijji.

Stellar frontier - A game by Stardock in 1997.

Strategy First - A video game software company

Speculative fiction, term coined by Robert A. Heinlein as a synonym for science fiction, but now refers to a literary genre which includes science fiction. Also abbreviated "spec-fic," "S-F", or "sf".

Sacrifice fly, baseball terminology

Spontaneous fission, a nuclear decay route in which a superheavy nucleus splits into two.

Tassili Airlines, IATA airline designator

Small Forward, a basketball position

Statsforetak, a type of Norwegian state enterprise

SourceForge, a collaborative software development management system

Suomen Filmiteollisuus, a Finnish film production company.

Stade Français Paris, a French rugby union team

Svensk Filmindustri, the Swedish Film Industry