The 25-year old, who was signed in the summer, has made a big impact at Portman Road this year and is already becoming a fans favourite.
Sito told the club website that when the fans sing his name it gives him "goosebumps."
He also added: "I have only been in England a short time but I love the football here. I love the passion."
Sito became the third Town player to extend his stay at the club today, after Gavin Williams signed a permanent deal from West Ham and 17 year old Danny Haynes also signed a 3 and a half year deal with the tractor boys.