The 'Behind Closed Doors' singer will perform at the Music On The Hill event in July, with all proceeds from the three-day festival going to the Demelza Hospice Care for Children, Teens Unite Fighting Cancer (founded by Karen Millen) and The Children's Development Trust.
On Monday (17 June), the star joined fashion icon Karen to visit the Demelza Hospice, where he spent time chatting with kids and learning more about what the hospice does.
He tweeted after his visit: "Amazing visit to @DemelzaHospice today for @MOTHFESTIVAL Met some brill kids."
Peter is no stranger to charity fundraising, recently launching a cancer charity foundation in memory of his late brother Andrew, who sadly passed away last year.
He has also undertaken a charity bike ride in Zanzibar for the HIPz charity – Health Improvement Project Zanzibar – peddling a gruelling 30 miles a day across ten days.
The Music On The Hill event will take place from 19 to 21 July at Kings Hill, West Malling, Kent. Other performers include Jools Holland, McFly, Stooshe, Joe McElderry and Gareth Gates.
More information and tickets are available here.