Growing up, Cormier played junior ice hockey before ending his career with the Quebec Major Junior Hockey League (QMJHL). However, after ending his playing career he wished to return as a linesman. After only a few years refereeing, Cormier was hired by the QMJHL as a linesman.[3] After officiating the 2003 World Junior Hockey Championship[4] and the Memorial Cup, he was offered a full-time position as a National Hockey League (NHL) referee.[2] He officiated his first career NHL game on October 10, 2003, in a game between the Pittsburgh Penguins and Los Angeles Kings.[5] His first time officiating an NHL Playoff Game was on April 22, 2006, between the New York Rangers and New Jersey Devils.[1] On December 2, 2018, Cormier officiated his 1,000th regular season NHL game.[6]