Demo, usually short for demonstration, may refer to:

• Demo (music), a song typically recorded for reference rather than for release
• Demo (Behind Crimson Eyes), a 2004 recording by the band Behind Crimson Eyes
• Demo (Deafheaven album), a 2010 EP by Deafheaven
• Demo (The Flatliners album), a 2002 album by the band The Flatliners
• Demo (Miss May I album), a 2008 recording by the metalcore band Miss May I
• "Demo", a 1990 single by Die Krupps
• "Demo" (P-Model song), a 1979 recording by songwriters Susumu Hirasawa and Yasumi Tanaka
• Demo (Skinless), a 1994 recording by the band Skinless
• Demo 2004 (Year of No Light album), a 2004 recording by Year of No Light
• Demo #2, an unreleased recording by Neutral Milk Hotel
• Demo, 2008 debut EP by Yuna

• Demo (computer programming), a multimedia spectacle of programming skill
• The Demo, a computer demonstration in 1968, sometimes called "the mother of all demos"
• DEMOnstration Power Plant (DEMO), a proposed nuclear fusion power plant
• Design & Engineering Methodology for Organizations (DEMO), an enterprise modelling methodology
• Demo mode, a feature often found in consumer electronics
• Game demo, a freely-distributed version of a video game
• Game replay, or demo, a recording of a video game which is played back within the game's engine
• Technology demo, a prototype version of a technology product

• Demo (ancient Greek poet) (fl. c. AD 200), ancient Greek poet
• Demo (zsnes), one of the authors of the ZSNES software emulator
• Demo Cates, Canadian musician; see Juno Awards of 1985
• dEmo (artist), Spanish artist (born 1960)
• Grillo Demo, Argentine artist

• Demo (comics), a comic book series by Brian Wood and Becky Cloonan
• A short form of Demonstration (protest)
• Demonstration (teaching), teaching by reason or proof using examples or experiments
• Product demonstration, a sales or marketing presentation
• Demolition, the destruction of buildings and other structures
• Exhibition game, a sporting event with no competitive value to any competitor
• DEMOs, a business process design methodology by Jan Dietz
• Demo, a daughter of the gods Celeus and Metaneira
• DEMO conference, held annually by IDG for new technology products
• d.e.m.o., a defunct clothing store owned by Pac Sun
• Demoman, one of the nine playable classes in Team Fortress 2

• Demoware, software that users can test in a limited fashion before buying
• Demographics, quantifiable statistics of a given population
• Demoscene, a computer art subculture that specializes in producing demos
• Demos (disambiguation)
• Democrat (disambiguation)
• Demolition (disambiguation)
• Demonstration (disambiguation)