Campbell will join Hayley Holt and the rest of the Breakfast presenting team from Monday, April 29.
In the meantime, Tame will move to weekly politics show Q+A on the same day, replacing Corin Dann who is leaving TVNZ.
Campbell said: "Breakfast offers the best of a live studio environment, with the opportunity to still work in the field – to me that's the perfect balance.
"It's a privilege to be part of New Zealanders' first news source of the day, bringing viewers breaking coverage from overnight, sharing stories that matter from around the country, and giving people a voice. I'm looking forward to joining the team."
He will continue to contribute his storytelling across other TVNZ news and current affairs programmes.
Holt, Daniel Faitaua and Matty McLean will continue to co-host the Breakfast show alongside Campbell.
Breakfast is on TVNZ1 weekdays from 6am-9am.
