Emma Willis is replacing Brian Dowling as the host of Big Brother.
Brian, 34, who won the reality TV show in 2001 and Ultimate Big Brother in 2010, has hosted the programme for two years since it moved to Channel 5.
Emma, 37, who is married to former Busted star Matt, is the host of spin-off show Big Brother's Bit On The Side.
The presenter, who will also front Celebrity Big Brother, said: "I am thrilled to have been offered this job.
"I'm a fan first and foremost so to be able to front the show is going to be amazing. Roll on the summer!"
Channel 5 director of programmes Ben Frow said: "Emma is a natural on screen, she's made the spin-off show her own and now the time is totally right for her to step up.”