Flex or FLEX may refer to:

• Apache Flex, formerly Adobe Flex, technologies for developing rich internet applications
• Flex (language), developed by Alan Kay
• FLEX (operating system), a single-tasking operating system for the Motorola 6800
• FlexOS, an operating system developed by Digital Research
• FLEX (protocol), a communication protocol for pagers
• Flex, a family of automatic test equipment produced by Teradyne
• FLEx, a piece of software used in language documentation
• Flex (lexical analyser generator), a lexical analyser generator and a free software alternative to lex
• Flex machine, a computer developed by RSRE in the 1980s
• CSS Flexible Box Layout, commonly known as Flexbox, a CSS 3 web layout model

• Bending, also known as flexure, as used in mechanics
• Flexion, in anatomy, a position made possible by the joint angle decreasing
• Femtosecond Lenticule EXtraction, a form of refractive eye surgery
• Flex circuit, a flexible printed circuit used in electronic assemblies
• FLEX mission, a future satellite launch mission by the European Space Agency
• Flex temp, a reduced takeoff thrust setting which trades excess performance for reduced engine wear
• Flex-fuel, a flexible-fuel vehicle
• Inflection point, of a curve in geometry
• Power cord, or flex, a flexible electrical cable

• Flex (singer), Félix Danilo Gómez (born 1974), Panamanian singer
• Funkmaster Flex (born 1968), American DJ and music producer
• Flex (album), Lene Lovich's 1979 second album
• Flex (EP) a 2003 EP by Pitch Black
• "Flex" (Dizzee Rascal song), 2007
• "Flex" (Mad Cobra song), 1992
• "Flex" (Polo G song), 2020
• "Flex (Ooh, Ooh, Ooh)", a 2015 song by Rich Homie Quan
• "Flex", a 2021 song by TFN
• Flex, a break in the recitation tone before the mediation in Gregorian chant
• A "flex" in a "flex bar", a technique used in battle rap

• Flex Ltd., a software compant, previously known as Flextronics
• Flex (club), a nightclub in Vienna, Austria
• Flex (company) (NASDAQ symbol: FLEX), a contract electronics maker based in Singapore
• Flex FM, a London-based radio station
• Flex-Elektrowerkzeuge, a German producer of power tools
• Flex Linhas Aéreas, a Brazilian regional airline

• Flex Alexander, Mark Alexander Knox (b. 1970), an American actor and comedian
• Flex Wheeler (born 1965), American bodybuilder
• Walter Flex (1887–1917), German author

• Amazon Flex, a platform for gig workers performing deliveries for Amazon
• Flex (comics), a fictional superhero
• Flex (film), a commercial/short film by English director Chris Cunningham
• Flex (magazine), an American bodybuilding magazine
• Flex (TV program), a 2021 Philippine variety show
• Fleet Landing Exercises, a series of landing exercises conducted by the Fleet Marine Force, a combined-United States Navy/Marine landing force
• Flex Your Rights, a civil-liberties non-profit based in Washington DC, US
• Ford Flex, a crossover SUV produced from 2009-2019
• Future Leaders Exchange, an American student exchange program for high school students from the former Soviet Union

• Bend (disambiguation)
• Flexible (disambiguation)
• All pages with titles beginning with Flex
• All pages with titles containing Flex