Listen: Hear a clip from Mae Muller's Eurovision entry I Wrote A Song
The news was revealed on Zoe Ball’s show on BBC Radio 2 on Thursday, 9 March.
The 25-year-old singer will perform at the event in Liverpool with her track I Wrote A Song, becoming the UK's first female solo Eurovision act in five years.
Read more: How many times has the UK won Eurovision?
It comes after rumours that Muller had been selected by BBC bosses and global management company TaP Music.
The singer revealed herself on the show, exclaiming: "Oh my God I have been wanting to say that for months!"
Muller told Ball and presenter Rylan that she had known for two months and that it had been tough to keep the secret to herself.
"That has been on my lips and in my brain and in my soul and it my nails!" she cried.
Muller, who was still working at a pub when she landed her first publishing deal, let slip a few details about her performance and costume, saying it was "already looking insane".
Her song was also played on the station and Ball said it was "a winner".
The pop star said of the song: "I wrote the song a few months ago when I was going through a hard time and wanted to feel empowered about relationships, so for it to be chosen for this year’s UK Eurovision song is honestly a dream!”
Last year Eurovision was won by Ukrainian act Kalush Orchestra, with the UK’s Sam Ryder runner-up.
This year’s contest should have been held in Ukraine, in keeping with the tradition that sees the event staged in the country of the previous year’s winner.
But it will be held in Liverpool this year amid the ongoing conflict with Russia.
— BBC Eurovision (@bbceurovision) March 9, 2023
Semi finals will be broadcast on BBC One and BBC iPlayer on Tuesday 9 May and Thursday 11 May at 8pm.
The Grand Final will be broadcast on BBC One and BBC iPlayer and via BBC Radio 2 and BBC Sounds on Saturday 13 May from 8pm.
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