Parallel universe

Parallel universe may refer to:

Science

 * Many-worlds interpretation of quantum mechanics, which implies the existence of parallel universes
 * Multiverse, the sum of all universes, e.g. everything that exists

Philosophy

 * Possible world, a construct in metaphysics to bring rigor to talk of logical possibility
 * Modal realism, an account of possible worlds according to which they are all just as real as the actual world
 * Extended modal realism, the view that all worlds, possible as well as impossible, are as real as the actual world

Arts and media

 * Parallel universes in fiction, a hypothetical self-contained plane of existence, co-existing with one's own
 * Alternate history, a genre of fiction in which historical events differ from reality
 * Alternative universe (fan fiction), fiction by fan authors that departs from the fictional universe of the source work

Literature, film, and television

 * "Parallel Universe" (Red Dwarf), a 1988 TV episode
 * Parallel Universes (film), a 2001 British TV documentary
 * Mirror Universe (Star Trek), a fictional parallel universe in the Star Trek franchise

Music

 * Parallel Universe (4hero album) or the title song, 1994
 * Parallel Universe (Garnet Crow album), 2010
 * Parallel Universe, an album by Plain White T's, 2018
 * "Parallel Universe" (song), by the Red Hot Chili Peppers, 1999
 * Parallel Dimensions (album), by Perseo Miranda, 2008