X Factor's Joe McElderry joined Alexis Jordan and the cast of the new Chronicles of Narnia film to switch on the Christmas lights in London's Regent Street.
Before the lights were turned on, he performed in front of thousands of people who had come to watch the event. The road was closed off to traffic for an hour.
Joe performed the track There's A Place For Us, a song which he has recorded for the new Narnia film, The Chronicles of Narnia: The Voyage of the Dawn Treader.
Alexis Jordan from America's Got Talent also performed for the crowds, just days after cruising to number three in the UK singles charts.
The stars from the new Narnia film, The Chronicles of Narnia: The Voyage of the Dawn Treader, Georgie Henley and Ben Barnes came along to help switch on the lights.
And then the all important moment came - the switching on of the lights! All the stars joined Joe McElderry .
And the lights are on! Here's a pic from the rooftops. Now the crowds can get on with their Christmas shopping.