Walsh is the only judge to have appeared on all series of the show so far since its launch in 2004. Confirming he has signed a contract, he also told The Mirror that he is unsure whether Kelly Rowland will return but hopes that she will commit to the panel for another run.
> Caroline Flack confirms 'Xtra Factor' 2012 return
"I am so happy to have signed up for another year," Walsh said. "It's my ninth year, I'm the only person to be in it for nine years... I'm busy now from here until Christmas. I signed the deal yesterday - making it my ninth year on the show.
"I never wanted to be on TV, it was never in my plan. But now I'm on it, I love the show."
Of who will be alongside him at the judges' table when the show returns, Walsh said: "I know two of the judges who are going to be beside me, but I still don't know who the fourth is going to be just yet.
"I know for definite that Tulisa [Contostavlos] is back, and Gary [Barlow] is back. I'm not sure if Kelly is back, but I hope she is, because she worked really hard last year."
> Simon Cowell blasts Tulisa sex tape 'scumbag': 'X Factor job is safe'
Contostavlos, Barlow and Rowland joined The X Factor last year, replacing Dannii Minogue, Cheryl Cole and Simon Cowell.
Cowell, who left the judges' table to focus on last year's launch of The X Factor USA, has said that he thinks all four X Factor UK judges will return to the programme.
Both Barlow and Contostavlos have said they are keen to stay on the show.
Watch Gary Barlow and Tulisa Contostavlos talking about The X Factor at the 2012 National Television Awards: