"Halcyon" is a song written and performed by Orbital, dedicated to Phil and Paul Hartnoll's mother, who was addicted to the tranquilliser Halcion (Triazolam) for many years.

On Orbital's second eponymous album the track "Halcyon + on + on" appears, a slightly more upbeat and melodic remix of the original song.

[4] "Halcyon" is one of the mainstays of Orbital's live performances, in which it is frequently remixed with clips from Belinda Carlisle's "Heaven Is a Place on Earth" and Bon Jovi's "You Give Love a Bad Name".

On occasion (notably the group's 2004 "last ever" performance broadcast on BBC Radio 1) it has also incorporated the chorus of "I Believe in a Thing Called Love" by The Darkness.

The song's video featured Opus III singer Kirsty Hawkshaw playing a typical mother who was 'under the influence' (which was shot in the Hartnolls' home), who begins her chores by washing dishes.