Tournaire becomes the second Leicester prop to sign with Perpignan after Perry Freshwater also opted to join the club in April.
The veteran French prop, who appeared in his side's 1999 World Cup Final defeat against Australia, has represented his country in 49 Tests and also tasted Grand Slam success with France back in 1997.
Tournaire, who was allowed to leave Leicester because to family problems, told AFP that he was more than happy to side for a club like Perpignan, adding: "They are an ambitious club and I have come here to win trophies."
The 30-year-old Tournaire becomes the third well-known international to sign for the ambitious Catalan club, after the French side secured the services of veteran Wallaby centre Daniel Herbert and injury-prone England winger Dan Luger.
Ireland lock Mick O'Driscoll and Narbonne lock Colin Gaston are two other names that have been confirmed in the squad for next season at the Stade Aime Giral, while All Black back rower Scott Robertson has reportedly also put pen to paper with the Heineken Cup Finalists.