Rick Edwards is to replace Nicky Campbell on BBC Radio 5 Live's Breakfast programme.
Edwards, who has previously fronted T4 and TV game show Impossible, will join co-host Rachel Burden on the show.
In a statement, he joked: "I realise I have some big boots to fill - I checked, and Nicky Campbell's an eye-watering UK12!"
The "new look" 5 Live Breakfast will launch in November, with Campbell moving to a new, later phone-in slot.
His new show will run from 09:00 to 11:00 and will be based on his current one-hour Your Call, which is presently part of the Breakfast slot.
"Congratulations to Rick," Campbell tweeted on Wednesday. "He's a brilliant broadcaster. Him and @RachelBurden gonna be fab."
Edwards, who has worked as a guest presenter on 5 Live since 2019, will join a daytime line-up that includes Naga Munchetty, Adrian Chiles, Nihal Arthanayake and Tony Livesey.
"When it comes to 5 Live, I'm a long-time listener, first-time breakfast-show-presenter," Edwards said in a statement.
"I've always loved the station's heady mix of news, sport and free-wheeling conversation. I realise I have some big boots to fill - I checked, and Nicky Campbell's an eye-watering UK12! - but I'm very excited about popping them on and sitting alongside the brilliant Rachel every morning."
The 42-year-old began his career as a stand-up comedian after graduating with a degree in Natural Sciences from the University of Cambridge.
He has since presented TV shows including River Hunters and BBC Three's Free Speech.
Burden, who has co-presented the weekday breakfast show since 2011, said: "It's a joy and a privilege to be starting a new chapter on 5 Live Breakfast with Rick.
"He has a love of sport and curiosity about the world which our 5 Live family will love. Plus he knows a lot about octopuses, which will surely come in handy at some point."