The Killers will also play at T in the Park and V Festival
An extra day has been added to Hard Rock Calling at Hyde Park in June with The Killers to join Neil Young and Bruce Springsteen as headliners.
The Kooks will support The Killers as the London festival starts a day early on Friday 26 June.
Tickets for the day will go on sale at 0900 BST this Friday. Further acts for the day are yet to be announced.
Tickets for the Saturday, headlined by Young, are on sale now. Springsteen's Sunday slot has already sold out.
Springsteen, 59, will be supported by acts including Dave Matthews Band and The Gaslight Anthem.
Acts including Fleet Foxes, Ben Harper, Seasick Steve and The Pretenders will support Young, 63, on the Saturday.
The Killers will also play at the T in the Park festival in Balado, Kinross-shire, in July, and August's V Festival, to be held in Essex and Staffordshire.