Singer Robbie Williams has paid tribute to acclaimed British stage designer Mark Fisher, who responsible for working on the London 2012 ceremonies, after he died today aged 66.
The Oxford Street lights are an iconic symbol of Christmas in the capital.
They were switched on tonight by Mr Robbie Williams, who is currently top of the charts.
Ria Chatterjee caught up with Robbie before the big switch:
Robbie Williams will turn on the Christmas lights in Oxford Street tonight.
He will be joined by both Leona Lewis and boyband Lawson - who will both also be performing at the event.
For the first time, the Christmas lights turn on is going to be ticketed, with tens of thousands expected to be attending.
We will be interviewing Robbie ahead of the switch on, on London Tonight at 6pm.
Robbie Williams has been added to the bill for the Queen's Diamond Jubilee Concert.
Event organiser Gary Barlow has asked his Take That bandmate to perform at the June 4 show happening in front of Buckingham Palace.
The line-up includes Elton John, Tom Jones, Jessie J and Ed Sheeran.
The Queen will watch the performance, along with the Duke of Edinburgh and other members of the Royal Family.
Robbie said: "If this doesn't get me a knighthood, nothing will. I can't wait for the show."