Acting great Sir Ian McKellen says he once rejected a nearly $2 million payday to dress up as Gandalf from The Lord of the Rings and officiate a wedding.

Nearly three years ago, Napster founder and first Facebook president Sean Parker asked Sir Ian, 77, to take part in his lavish $10 million Tolkien-themed wedding, The Daily Mail reported.

But Gandalf declined the loaded invitation.

“I was offered one-and-a-half million dollars (US) to marry a very famous couple in California, which I would perhaps have considered doing, but I had to go dressed as Gandalf,” he said.

“So I said, ‘I am sorry, Gandalf doesn’t do weddings’.”

The internet tycoon, who is said to be worth as much as $2 billion, according to Forbes magazine, invited 364 star-studded guests including Sting, Sean Lennon and Emma Watson.

Other extravagances included donning custom-made outfits by Lord Of The Rings costume designer Ngila Dickson, a 3m-high wedding cake and a pen of white bunnies for “anyone who needs a cuddle”.

Sir Ian has once conducted the wedding of best friend and Star Trek actor Sir Patrick Stewart and fiancee Sunny Ozell in 2013.