The outspoken Osbourne was one of the original X Factorjudges in Britain from 2004 through 2007.
In the first format change announced for the 10th season, hopefuls will have to survive two sets of auditions. First, they will face the judges in an intimate audition room. If they receive three or more yes votes, they will have to perform for the judges in an arena "to prove they can also impress an audience before securing a place at the next stage in the competition," according to the producers.
Said Cowell: "Three words I never thought I'd say: Welcome back Sharon!"
Said Osbourne: “I couldn't be happier about coming back for the 10th anniversary of X Factor. I can't wait to give Gary Barlow a big hug, sit next to the gorgeous Nicole, and of course throw water on dear Louis. Yay!"
Peter Fincham, director of television at ITV, said: "We're delighted to confirm our fantastic panel, who will bring an incredible combined wealth of experience to our 10th series of The X Factor. I know I speak for all of us when I say we're looking forward to bringing viewers a brilliant series this autumn."