Coachella's Twitter account posted a photograph of the full line-up today (09.01.14), along with message: ''Share it like a polaroid picture! OutKast, Muse, Arcade Fire + more #Coachella. (sic)'', in reference to OutKast's hit song 'Hey Ya' from their 2003 album 'The Love Below'.
OutKast were already rumoured to be on the bill after producer Rico Wade told music website Stereogum they would be reforming after a seven-year hiatus.
Newcomers HAIM, Lorde, and Disclosure also received top billings for the event, which takes place from Friday, April 11 to 18.
Tickets for Coachella 2014 have been on sale since May last year but today's announcement caused Coachella.com to crash within minutes of the line-up being posted.
OutKast haven't worked together since they created the soundtrack for the 2006 musical film, 'Idlewild', and have been discussing a reunion for some time.
Since 2007, they have been on hiatus and both members have pursued solo careers, although the group moved to Epic Records in 2011.