Look up observer in Wiktionary, the free dictionary.

An observer is one who engages in observation or in watching an experiment.

Observer may also refer to:

Computer science and information theory

• In information theory, any system which receives information from an object
• State observer in control theory, a system that models a real system in order to provide an estimate of its internal state
• Observer pattern, a design pattern used in computer programming

Fiction

• Observer (novel), a 2023 science fiction novel by Robert Lanza and Nancy Kress
• Observer (video game), a cyberpunk horror video game
• Observer (Mystery Science Theater 3000), a fictional television character
• Observers, beings in the television show Fringe

Military

• Air observer, an aircrew member
• Artillery observer, a front line personnel who directs fire discipline for artillery strikes
• Royal Observer Corps, a civil defence organisation, originally tasked with reporting enemy aircraft
• Observer, a non-participating officer, or umpire, tasked with observing the actions of soldiers during a field training or military exercise

Music

• "Observer", a song by Gary Numan on his album The Pleasure Principle
• "The Observer", a track from The Flaming Lips' 1999 album The Soft Bulletin
• The Observers, an alternative name for reggae session band Soul Syndicate
• Niney the Observer (born 1951), Jamaican record producer and singer

Publications

• Observer.com, an online-only version of the weekly newspaper The New York Observer
• Sunday Observer (Sri Lanka), a weekly newspaper
• Observer (APS), a member magazine of Association for Psychological Science
• The Observer (disambiguation), any of various periodicals

Science

• Observer (general relativity)
• Observer (meteorological)
• Observer (physics)
• Observer (quantum physics)
• Observer (special relativity)
• Observational astronomy

Other uses

• Observer status, granted by an organization to allow a non-member limited participation
• An election observer, one who assists in election monitoring
• A game official sometimes used in the sport Ultimate
• The Observer type in the Enneagram of Personality model
• Donald Alaster Macdonald (1859–1932), Australian journalist who wrote under the pseudonym 'Observer'

See also

• Observer effect (disambiguation)
• National Observer (disambiguation), a variety of publications
• United Nations Military Observer
• All pages with titles containing Observer