Lux Aeterna is a piece for 16-part mixed choir, written by György Ligeti in 1966. It is most famous for its use in Stanley Kubrick's 1968 film 2001: A Space Odyssey.

The text (in Latin) is from the Roman Catholic Requiem Mass: Lux aeterna luceat eis, Domine, cum sanctis tuis in aeternum, quia pius es. Requiem aeternam dona eis, Domine; et lux perpetua luceat eis, which means "May everlasting light shine upon them, O Lord, with thy saints in eternity, for thou art merciful. Grant them eternal rest, O Lord, and may everlasting light shine upon them."