The singer, who made her comeback with new single "Hard out here", confirmed the news on Nick Grimshaw's Radio 1 Breakfast Show Tuesday, reports contactmusic.com.
"It got confirmed yesterday," she said Tuesday.
"I'll be doing 16 weeks of festivals over the summer and then tour," she said, adding that Glastonbury would be her first "big" gig of 2014.
"It's the best festival, I think - that, and Fuji Rock in Japan."
Glastonbury Festival, to be held June 25-29, 2014, will see a congregation of various arts like contemporary music, dance, comedy and theatre.
--IANS (Posted on 20-11-2013)