If

If most often means:

If or IF may also refer to:

Arts and entertainment

IF, a character in the Hyperdimension Neptunia game series
Interactive fiction, text-based computer games featuring interactive stories and environments
Shin Megami Tensei If..., a 1994 video game in the Shin Megami Tensei series
Kill la Kill the Game: IF, a 2019 video game based on the Kill la Kill anime

If (magazine), subtitled "Worlds of Science Fiction"
IF Magazine, Inside Film, Australian magazine, known for IF Awards
If... (comic), a political comic strip which appears in the UK newspaper The Guardian
"If—" (published 1910), a poem by Rudyard Kipling
The laconic phrase "If", a Spartan reply to a threat by Philip II

"If..." (The Bluetones song), 1998
"If" (Bread song), 1971, covered by many artists, including a UK #1 by Telly Savalas in 1975
"If" (Davido song), 2017
"If" (French Kiss song), 2011
"If" (Glasvegas song), 2013
"If" (Janet Jackson song), 1993
"If" (Kana Nishino song), 2010
"If" (Pink Floyd song), 1970
"If (Mata Aetara)", by Day6, 2018
"If (They Made Me a King)", written by Tolchard Evans, Robert Hargreaves and Stanley J. Damerell, 1934; notably recorded by Perry Como, 1950
"If", by Jeri Lynne Fraser (as Jeri Lynn), 1959
"If", by Femme Fatale from Femme Fatale, 1988
"If", by The Cult from Ceremony, 1991
"If", by Joe Satriani from his 1995 self-titled album
"If...", by The Divine Comedy from A Short Album About Love, 1997
"If", by Bananarama from Exotica, 2001
"If", by Destiny's Child from Destiny Fulfilled, 2004
"If", by Red Hot Chili Peppers from Stadium Arcadium, 2006
"If", by Freemasons from Unmixed, 2007
"If", by Joni Mitchell from Shine, 2007
"If", by R5 from New Addictions, 2017

If (band), 1970s British progressive jazz-rock band
In Flames, a melodic death metal band from Sweden, and a song from their album Lunar Strain
I-F, stage name of Ferenc E. van der Sluijs, a Dutch producer and DJ

If (insurance company), in the Nordic countries
IF Metall, a trade union in Sweden
Illuminati Films, an Indian motion picture production, based in Mumbai
Independent Fabrication, a bicycle manufacturer
Intelligent Finance, a bank
Interflug (1958–1991; IATA airline designator IF)
International Federation, any of several world sport governing bodies
International Forum Design (iF), a society best known for its iF design awards
Islamic Front (Syria), Sunni Islamist rebel group involved in the Syrian Civil War
Islas Airways (founded 2002; IATA airline designator IF)

If-then-else, a conditional statement in computer programming
IF (x86 flag), the Interrupt Flag in the x86 processor architecture
Information filter, or inverse covariance filter, in Kalman filtering
Interface (computing), a shared boundary across which components of a computer system exchange information
Intermediate form, a type of data structure in computer programming
Infinity Fabric

Information filtering system, which removes redundant or unwanted information at a semantic level
Intelligent falling, a satirical "alternative theory" of gravitation
Intermediate frequency, in radio transmission or reception
Internal focusing, a lens technology in which focusing occurs only with internal elements
Iodine monofluoride, an unstable interhalogen inorganic compound
International Fujita scale (IF-scale), a scale to rate a tornado's intensity

If, a small island in the Bay of Marseille, France; location of the Château d'If
Impact factor, a measure reflecting the average number of citations to articles published in scholarly journals
Intellectual freedom, a right to access, explore, consider, and express ideas and information
Intermittent fasting, a diet having recurring periods of fasting
Internally Flawless, a grade of diamond clarity
Inside forward, a position in association football
Ilfov County (except Bucharest), on the vehicle registration plates of Romania