The Coyotes announced the trade Wednesday night.
This will be Lombardi's second stint in Phoenix. The 30-year-old skated for the Coyotes from 2008-10, notching 24 goals and 45 assists before being traded to the Nashville Predators. He signed as a free agent with the Maple Leafs in the summer of 2011.
"We are very pleased to bring a player like Matthew back to our team," general manager Don Maloney said in a statement. "Matthew is a very strong skater who will add quickness and skill to our lineup. He is an intelligent center who will be a great addition to our team and provides us with added depth at the center position."
Lombardi had eight goals and 10 assists in 62 games for Toronto last season.