A native of Montreal, Quebec Thibault played in the Queve Midget AAA Hockey Leauge with the Laval Regents before starring in the QMJHL with the Trois-Rivieres Draveurs and Sherbrooke Faucons where he was named the CHL's Top Goaltender in 1993. He was claimed 10th overall by the Quebec Nordiques in the 1993 NHL Entry Draft and was a solid back up to Stephane Fiset for two seasons.
The young backstopper remained with the franchise when it relocated to Colorado in 1995. His life changed dramatically when he was sent to Montreal as part of the package used to obtain Patrick Roy. Initially things went well for Thibault as he posted a 23-13-3 record as he helped the Habs reach the playoffs under coach Mario Tremblay. Thibault went on to play parts of four seasons with the Canadiens before being dealt to the Chicago Blackhawks in a multi-player deal that also involved veteran netminder Jeff Hackett.
Upon his arrival in Chicago, Thibault became a workhorse with the Hawks and had five straight seasons with at least 20 wins before suffering a season ending injury early into the 2003-04 season.
Following a lock out year in 2004-05, Thibault was acquired by the Pittsburgh Penguins in the summer of 2005, after the Blackhawks had acquired Nikolai Khabibulin from the Tampa Bay Lightning.
In Pittsburgh, Thibault backstopped the young netminder Marc Andre Fleury over two seasons while appearing in 38 games. In his first season with the Penguins, Thibault struggled to find his form, recording only one win in ten starts. The following season, Thibault appeared in 22 games and compiled a respectable record of 7-8-2 as the Penguins surged toward the latter half of season.
In the summer of 2007, the veteran goaltender signed a one-year contact with the Buffalo Sabres.