Azealia Banks, Billy Bragg and St. Vincent are also due to appear at the Gothenburg event.
© PA Images / Chris Pizzello/AP
© Rex Features / Tom Watkins
Way Out West 2012 will run for three days starting from August 9.
The show, which is held in a 137 hectare park, won the 'Most Innovative Festival' award at last year's MTV O Music Awards.
The 2011 lineup included Pulp, Noah and the Whale, Fleet Foxes and The Hives.
One of last year's more notable moments saw Kanye West join Prince on stage.
> More summer festival headlines
Watch the Florence + The Machine 'Lover To Lover' music video below:
