The I’ll Be There singer and band The Human League will both be headlining the summer event.
Sister Sledge and Big Shaq are also among the names announced for the family festival.
Spice Girl Mel C will DJ, “taking to the decks with a 90s mixtape and some serious girl-power”.
Other stage acts and DJs include The Wailers, Sara Cox, Morcheeba and Goldie.
Camp Bestival curators Josie and Rob da Bank said: “Camp Bestival is back with a bang and we’re over-the-moon to announce our return with the best and biggest line-up to date in 2019.
“Expect magical mania, brimmed with momentous music, phenomenal feast-worthy food and exciting experiences suited for everyone, whether you’re aged eight or 80!”
The festival, which also features family raves and silent discos and a new children’s area designed to discourage screen time, takes place at Lulworth Castle, Dorset, from July 25 to 28.