Faithless, The Script, Jess Glynne and Example have also been added to the lineup for Barclaycard presents The Isle of Wight Festival, which has been running since 1968.
The five-day festival takes place in June and draws in around around 200,000 music fans each year.
The festival is yet to announce the full line-up, but previous years have saw Calvin Harris, Swedish House Mafia and Tiesto take to the stage.
With chart-topping hits like Your Song and Let You Love Me, Rita’s high-energy performance will be a highlight at the UK’s largest family-fundraising festival.
The official Glastonbury tickets went on sale on November 14 and November 17.
