The Radio 1 DJ currently presents the channel's Freshly Squeezed and will take up his new role alongside Jameela Jamil from April 23.
"When I got the call from Channel 4 asking me to join their best team of presenters I thought, 'Won't I end up being a third wheel in the Phil and Kirsty dynamic?' Then they clarified that they were talking about T4, which is almost as good," he said.
"Given the recent departure of Steve Jones, I can understand why they have chosen an equally attractive replacement. I look forward to bothering popstars and introducing Hollyoaks on your TV soon."
Speaking of Edmondson's appointment, head of T4 and music Neil McCallum said: "We're delighted that Matt has decided to officially join the T4 presenting team after several chance encounters.
"Last year we were particularly impressed with his work across T4 shows such as Pocket TV and through his coverage of RockCorps and the V Festival. His dedication, charm and thorough knowledge of all things T4 meant it was only a matter of time before he'd permanently infiltrate the team and join ranks with Rick Edwards, Jameela Jamil, Nick Grimshaw and Georgie Okell. It's great to have him on board."
It was recently confirmed that Edmondson, who presented online series The F Factor last year, is to take over Huw Stephens's Wednesday night slot on Radio 1.
> Click here to read our previous interview with Matt Edmondson