The former Aston Villa manager was on hand to see the Black Cats slip to defeat at Wolves on Sunday but he does not officially take charge until Monday morning at the club and he is delighted to have got the job and to be back in football.
O'Neill signed a three-year deal on Saturday and the former Leicester, Celtic and Aston Villa manager is excited to be back in the game.
"It's a nice feeling to be back in football and obviously I'm very excited about joining Sunderland," he told SAFC TV. "It's a big moment and I'm hoping it works out well.
"Naturally I want to do well for the fans, the team and myself. If we can combine all this and start winning football matches it would be terrific. All I can say, without promising the earth, moon and stars is I will do my utmost to bring a bit of success to Sunderland."
He added: "I would like it to be a really successful period and I'm going to try my best to achieve that. That's what I've come for - that's what I want to do."