The Albania midfielder becomes Black Cats boss Steve Bruce's third signing of the summer following the arrivals of Paraguay skipper Paulo Da Silva and England Under-21 striker Fraizer Campbell.
Bruce told the club's official website: "I'm delighted to have brought Lorik to the club, especially given the number of clubs who had expressed an interest in signing him."
Bruce added: "He brings with him a tremendous amount of experience both at club level and internationally and is a great addition to our squad.
"To captain a side of Marseille's stature says a lot about the player and his character, and I'm sure he'll go on to be a fantastic signing for Sunderland."
Cana joined Marseille from Paris St Germain in 2005.