An event horizon is a boundary around a black hole inside which events cannot affect an outside observer.
Event horizon or Event Horizon may also refer to:
Event Horizon Telescope, an array of radiotelescopes that form an astronomical interferometer One type of geological horizon Event Horizon Software, the original name of American computer game developer DreamForge Intertainment Event Horizons BBS, a bulletin board system that ran from 1983 to 1996
Art and media Event Horizon, a fictional company in the novels of the Greg Mandel trilogy (1993–1995) by English science fiction writer Peter F. Hamilton Event Horizon (film), a 1997 science fiction horror film Event Horizon (album), a 2012 album by I Am I "Event Horizon" (Supergirl), a 2019 episode of Supergirl Event Horizon, the lead single from the 2021 album End Theory by Younha (in Korean) "the event horizon", a 2019 poem by Simon Armitage to commemorate opening of Halle St Peter's extension Event Horizon (sculpture), a 2007 site installation by Antony Gormley
See also Event Horizon Telescope, international collaborative project Horizon (general relativity)