	Théodore played major junior in the QMJHL for four seasons with the St-Jean Lynx and Hull Olympiques. At age 16, he began his major junior rookie season in 1992–93, splitting goaltending duties with Jean-Pascal Lemelin. He assumed the starting position the following season in 1993–94, recording a 3.61 goals against average (GAA) with a 20–29–6 record. Théodore was drafted that off-season by the Montreal Canadiens 44th overall in the 1994 NHL Entry Draft.