DJs Fearne Cotton and Reggie Yates are to host the weekend breakfast show on BBC Radio 1 from the end of September.
The pair visited the US last summer to film Only in America for CBBC
They will take over from Spoony, who is leaving after six years to concentrate on his passion for sport at another BBC station, Five Live.
The pair currently appear on the station's early morning show on Friday and were previously seen as presenters on the recently axed Top of the Pops.
The pair are "total stars", said Ben Cooper, Radio 1's head of mainstream.
He wished Spoony well, saying he had "done a great job for the station" and had "an amazing career ahead of him".
The schedule changes mean Cotton and Yates will be on-air between 0700 and 1000 each Saturday and Sunday.