The 25-year-old goalkeeper ended his eight-year stay at Arsenal when he accepted the Black Cats' offer of a two-year contract, and he is ready to tackle the next phase of his career on Wearside.
Mannone, who is understood to have cost around £2million, was the club's sixth summer signing and he told the club's official website: "The potential [of the club] is incredible. I have come from a big club but to be honest, I don't see any difference in the facilities."
He added: "From what I can see on my first day, they are brilliant. To have good facilities where you can work and improve is something every club wants to achieve.
"The base is there and I am really happy to be here. I waited a long time for an opportunity like Sunderland, and for me it is a great one. I'm very excited. I am here to work hard and to show what I can do."
Mannone's initial task will be to prove to Paolo Di Canio that it is he and not Republic of Ireland international Keiren Westwood to whom the challenge of keeping out the Barclays Premier League's leading marksmen should be entrusted.
He managed only 26 senior appearances for the Gunners, but four of them came in last season's Champions League, a measure of the trust placed in him by Arsene Wenger.
However, Westwood has had to wait patiently in line behind Belgium's Simon Mignolet for a chance to regain his place as Ireland's number on with manager Giovanni Trapattoni turning to David Forde because of his lack of club football, and he will be in no mood to pass up the opportunity handed to him by Mignolet's £9million departure for Liverpool.
Mannone walked through the door at the Academy of Light well aware of the challenge ahead of him, but ready to take it on.
He said: "Of course, every player knows they have competition. We live in a world of competition. I will work and do my best to be in the first eleven, and then the manager will decide. All I can do is try to show what I am capable of."
- Sports & Recreation