The Take That singer welcomed the latest permanent member of the ITV talent show's judging panel along with Louis Walsh and Tulisa Contostavlos.
He said that the former Pussycat Dolls frontwoman was the best out of all the recent guest judges, which included Geri Halliwell, Leona Lewis and Anastacia.
"I'm made up. I thought all the guest judges were excellent but she had the edge," he is quoted as saying in The Sun.
"She's exciting, has years of experience and was great on the US X Factor."
Nicole Scherzinger was officially confirmed as the fourth permanent judge on the show last week.
She claimed that her appointment proves that she was not sacked on the US version of the show after one season by Simon Cowell.
Gary Barlow had previously backed Mel B as the next permanent fourth judge.