Dizzee Rascal headlines Friday night at the festival, with Roxy Music topping the bill on the Saturday and Grace Jones closing the main stage on the final day.
Roxy Music frontman Bryan Ferry said: "There is a song on my album that I have co-written with my friends Groove Armada.
"They asked me if Roxy would like to perform at Lovebox. We of course thought it would be cool."
Other acts booked to play over the three-day event include Ellie Goulding, Noisettes, Mark Ronson and the Business, Empire Of The Sun, Rox, Booka Shade, Hot Chip, Peaches and Hurts.
A one-day ticket is priced at £45, with two-day tickets available for £80 and a full festival pass for £99.