The 63-year-old singer originally said that he and partner David Furnish would probably not make it onto the guest list, but has since confirmed that they will be attending.
He told Canada's CTV, 'We do have an invitation. I've been trying to be discreet.'
The flamboyant star was a close friend of Prince William's late mother, Princess Diana, and said that bride-to-be Kate Middleton 'is Diana in personality. She is very discreet - she is a very beautiful girl. They have been together a long time and I think she has handled the pressure so much.'
And he added that he would like to see William take to the throne sooner rather than later.
'William has one of the hardest jobs in the world.
I hope he becomes King at an early age. I think we need young people like him to lead. I think he will be a tremendous king.'