Olympiacos confirmed the move on Wednesday, with the 31-year-old introduced to hundreds of the club's supporters in Piraeus.
Saviola - who will wear the number 9 shirt at the club - was a free agent after leaving La Liga outfit Malaga in the close-season.
He scored nine goals in 37 appearances in all competitions last term, and featured six times in the UEFA Champions League.
Saviola - who counts Real Madrid, Barcelona and Benfica as some of his former clubs - was also linked with a switch to English Championship side Queens Park Rangers.
But he sealed his future on Wednesday, signing a deal that will boost Greek football after a tumultuous period in which several of the league's big names have left due to the country's well-documented financial problems.
