Fictional entities

• Omega (Doctor Who)
• Omega, a Maximum Ride character
• Omega, the fictional government agency in the film True Lies
• Omega, in the Mega Man Zero series
• E-123 Omega, a Sonic the Hedgehog character
• Omega, or Genra, a Dead or Alive character
• Omega 13, a time machine in the 1999 science fiction/comedy film Galaxy Quest
• Omega Ranger, a Power Rangers S.P.D. character
• Omega Rugal, a The King of Fighters character
• The Omegas, in the 2006 film X-Men: The Last Stand
• Omega, in Star Wars: The Bad Batch
• Omega OS, a fictional operating system in the 2018 game PC Building Simulator
• The Omega (Ninjago), a character in Ninjago
• Omega Flowey, a villain in the game Undertale
• Omega, the tier 100 skin of the Chapter 1, Season 4 Battle Pass in Fortnite: Battle Royale

Film and television

• Omega (film), a 2008 Greek film
• "Omega" (Dollhouse), the 12th episode of the TV series Dollhouse
• "The Omega Directive", an episode of Star Trek: Voyager, involving a substance called "Omega"
• "Omega" (The Walking Dead), an episode of the television series The Walking Dead

Literature

• Omega (Harris novel), by Christine Harris, 2000
• Omega (McDevitt novel), Jack McDevitt, 2003
• Omega (Leonard novel), by Raymond Leonard, 1986
• Omega: The Last Days of the World, an 1894 science fiction novel by Camille Flammarion
• Omega the Unknown, an American comic book by Marvel Comics

Music

Other uses in arts, entertainment and media

• Omega (audio drama), based on Doctor Who
• Omega (video game), 1989
• Omega (journal), an academic journal dedicated to the study of death and dying
• Omega Mart, an interactive art installation by Meow Wolf

Astronomy and astrodynamics

• Ω, the density parameter in Friedmann equations
• Omega Centauri, a globular cluster in the constellation of Centaurus
• Omega Nebula, a star cluster
• Argument of periapsis, abbreviated ω
• Longitude of the ascending node, abbreviated Ω

Computing

• Omega (T_eX), an extension of the typesetting system
• Omega Drivers, third-party drivers for ATI and nVidia graphics cards
• Ωmega, a strict pure functional programming language
• Omega language, in formal language theory
• Omega2 (computer), by Onion

Mathematics

• Chaitin's constant, or halting probability, written as Ω
• Lambert W function, or omega function
  • Omega constant, a specific value derived from the Lambert W function
  • Wright omega function
• ω, the first infinite ordinal number, also understood as the set of all natural numbers
  • ω₁ or Ω, the smallest uncountable ordinal number
• ω and Ω in big O notation
• Omega and agemo subgroup, in group theory
• Ω, an element in a subsumption lattice
• Prime omega function , in number theory

Other uses in science and technology

• OMEGA, an instrument on Mars Express Mars orbiter
• OmegA, a cancelled space launch vehicle
• Omega (navigation system), the first worldwide radio navigation system
• OMEGA laser, at the Laboratory for Laser Energetics, University of Rochester, New York, U.S.
• Angular frequency, ω, in physics
• Angular velocity, ω, in physics
• K_a/K_s ratio, or ω, in genetics
• Ohm, symbol Ω, the unit of electrical resistance
• Omega equation, in meteorology
• Omega loop, a protein motif
• Omega baryon, a sub-atomic particle
• OMEGA process, an industrial chemical process to produce ethylene glycol from ethylene