BBC television presenter Fearne Cotton is joining Radio 1 to co-present the early breakfast show on Fridays.
Yates and Cotton have presented Top of the Pops together
Cotton, 22, will host the morning slot with Top of the Tops co-presenter, Reggie Yates, from 30 September.
Radio 1 regulars JK and Joel will present the show, which starts at 4am, during the rest of the week.
Cotton, who presented backstage from Live 8, said: "I'm looking forward to talking about music, obsessing about music and playing loads of music."
"I'm so excited about joining Radio 1."
"When I was a kid I did the classic thing of taping shows off the radio and dropping my own voice in - hopefully this show will be better than that."
Yates added: "It'll be brilliant, Fearne and I are proper mates and we both have a genuine love of music."
A Radio 1 spokesman welcomed the move, saying said: "Reggie and Fearne are really hot at the moment and I'm chuffed they are ready to get up early to do this show.
"It'll be an ultimate guide to what to do at the weekend, and as they are passionate about different types of new music, love going to different gigs and generally having a good time, it should make for some great radio."
Nemone Metaxas, who currently presents the early breakfast show, will be leaving the station in September.
The early morning slot gave current breakfast host Chris Moyles his break at the station in 1997, turning it into a cult favourite.