The acts will play the three-day music event on July 8.
© PA Images / Matt Crossick/EMPICS Entertainment
© WENN
Labrinth has also been confirmed to perform at the London-based festival, which recently announced Rihanna as its first headliner.
It is expected that Harris will join the Bajan star on stage for a rendition of their global chart-topper 'We Found Love', which was named as Facebook's most listened to song of 2011 earlier this week.
Tickets for the festival, which takes place in Hyde Park between July 6-8, are on sale now and further acts are due to be announced in the near future.
The Wireless 2011 lineup included headline performances from the Black Eyed Peas, The Chemical Brothers and Pulp.
> Jessie J: 'I want to do a bigger tour next year'
Watch the music video for Jessie J's 'Who You Are' below:
