ESPN.com's Pierre LeBrun reports the contract is worth $11.4 million total, averaging $3.8 million a year.
The signing reunites the physical defenseman with Toronto general manager Brian Burke, who was Beauchemin's GM with the Ducks.
"I try to play an aggressive style of game," Beauchemin said during a conference call. "Solid in the D-zone, I try to contribute offensively when I can, I just try to be hard to play against."
The 29-year-old Beauchemin missed 62 games last season due to a knee injury, but returned to play in the final two regular-season games and all 13 playoff contests for Anaheim.
"Francois will be a welcome addition to our blue-line," Burke said. "He's a rock solid, steady defender that will add character to our team."
In other moves Monday, the Maple Leafs gave Nazem Kadri, the seventh overall pick in last month's NHL draft, a three-year entry level deal. Toronto re-signed forwards Ben Ondrus and Ryan Hamilton to one-year contracts and added free-agent forwards Jay Rosehill (two years), Tim Brent (one year) and Richard Greenop (three-year, entry level contract).
Information from ESPN.com's Pierre LeBrun and The Associated Press was used in this report.