The Ducks announced the deal Monday.
Santorelli had 12 goals and 21 assists last season while splitting time between Toronto and Nashville, which reacquired him in a multiplayer trade in February.
He also made his first NHL playoff appearances last spring with the Predators, who drafted him in 2004.
The Ducks are the sixth NHL team for the 29-year-old Santorelli, who also has played for Vancouver, Winnipeg and Florida.
He should help out down the middle on the Ducks' depth lines while Nate Thompson is sidelined early in the season.
Thompson had shoulder surgery in June. He isn't expected to return before December at the earliest.