The Maple Leafs made the announcement Wednesday.
The 31-year-old sat out all of last season to rehabilitate his left knee after undergoing realignment surgery in October.
Van Ryn last appeared in a game for the Maple Leafs on March 7, 2009.
In 353 career games for St. Louis, Florida and Toronto, Van Ryn has 30 goals and 129 points.
Van Ryn becomes an unrestricted free agent Thursday.