Annie will take over from the outgoing Zane Lowe from Monday 9 March.
The Irish presenter and DJ is known for kick starting Radio 1’s weekend on Friday evenings with her flagship dance music show.
She will continue to host her Friday evening slot on the network, but will step down from her hosting Radio 1’s Musical Hot Water Bottle on Sunday evenings.
Annie said: ‘I am so excited and humbled to be asked to do this show. The thing I love about music radio is those private epiphanies it provides. Having 11 hours of airtime a week to share those moments with music that has no boundaries, is beyond a job, it’s a privilege.
‘And to be following in the footsteps of Zane Lowe, a broadcaster that I respect and admire enormously, is a huge honour. I can’t wait to get started.’
Zane Lowe is moving to the US to take up a new role with software and music giant Apple.
Annie began her career with the broadcaster working as Zane’s broadcast assistant.