Scott Mills said he is "beyond excited" to replace Zoe Ball on the BBC Radio 2 Breakfast Show following her departure next month.
Ball, who took over the Radio 2 morning programme in 2019 from Chris Evans, announced on Tuesday she was stepping back from the show after six years to focus on her family.
She will host her last show on December 20 with Mills, who currently hosts Radio 2's weekday afternoon programme from 2-4pm, set to begin fronting the programme from early January.
In a statement, Mills said: "Zoe and I have been such good friends now for over 25 years and have spent much of that time as part of the same radio family here at Radio 2 and also on Radio 1.
"She's done an incredible job on this show over the past six years, and I am beyond excited to be handed the baton.
"It feels ever since recording my first shows as a kid for an audience of one, my mum, all roads since have led to this amazing opportunity.
"It really is a lifelong dream come true to follow in the footsteps of Sir Terry, Chris and Zoe to be the new presenter of the Radio 2 Breakfast Show."
Announcing the news on her Tuesday show, Ball said: "After six years of fun times alongside you all on the breakfast show, I've decided it's time to step away from the early alarm call and start a new chapter.
"You know I think the world of you all listeners, and it truly has been such a privilege to share the mornings with you, to go through life's little ups and downs, we got through the lockdown together, didn't we?
"We've shared a hell of a lot, the good times, the tough times, there's been a lot of laughter. And I am going to miss you cats."
She added: "But I won't miss the 4am alarm call, if I'm completely honest."
Ball took a break from hosting her show over the summer, returning in September.
She was the BBC's highest-paid on-air female presenter in 2023/24 with a salary between £950,000 and £954,999, ranking her second on the list of top-earning talent behind Gary Lineker, according to the corporation's annual report published in July.
She was the first female host of the Radio 1 Breakfast Show in 1998, a post she held until 2000, and she also co-hosted the BBC's Saturday morning children's magazine Live & Kicking alongside Jamie Theakston for three years from 1996.
Discussing her last show on December 20, she added: "Just in time for Christmas with plenty of fun and shenanigans. While I'm stepping away from the Breakfast Show, I'm not disappearing entirely - I'll still be a part of the Radio 2 family, with more news in the New Year.
"I'm excited to embrace my next chapter, including being a mum in the mornings, and I can't wait to tune in on the school run!".
She said in a statement that her and Mills were close friends and added: "I'm beyond thrilled it's him taking over the Breakfast Show.
"Breakfast has always been his dream, and what a year he's had - from racing around the world to his beautiful wedding to Sam. He's not only a blooming brilliant producer but one of the best in radio."
Helen Thomas, head of Radio 2, said: "Zoe has woken up the nation on Radio 2 with incredible warmth, wit and so much joy since January 2019, and I'd like to thank her for approaching each show with as much vim and vigour as if it were her first. I'm thrilled that she'll remain an important part of the Radio 2 family."
Thomas said it was a "privilege" to welcome Mills to the Breakfast Show and added: "He's a multi-award winning broadcaster who has been working in radio since the age of 16 and I know he can't wait to get started on the biggest Breakfast show in the land!".
Ball has presented the BBC spin-off show Strictly Come Dancing: It Takes Two, and ITV's reality competition show Mamma Mia! I Have A Dream.