Born in Red Deer, Alberta, Chris Mason played in the AMHL with the local Chiefs. He then played with the Victoria/Prince George Cougars franchise in the WHL and was drafted 122nd overall by the New Jersey Devils in 1995. He was unable to come terms with the Devils so he ended up signing with the Mighty Ducks of Anaheim in June, 1997.
Mason played 47 games as a rookie pro with the AHL's Cincinnati Ducks in 1997-98. In the off-season he was traded to the expansion Nashville Predators and made three appearances for them in 1998-99. He spent most of the next three season excelling with the IHL's Mlwaukee Admirals while receiving the occasional recall to Nashville.
In 2003-04, Mason was named the Predators back-up behind goaltender Thomas Vokoun. Mason would appear in 17 games that season and finish with a 4-4-1 record before competing in Vålerenga Ishockey of the Norwegian league during the year of the lockout.
In 2005-06 Mason spent the majority of the season with the Preds backing up Tomas Vokoun. However, Mason would become the starting goalie with the club toward the end of the season as Vokoun was lost for the year with a blood condition. Although the the Predators would be eliminated in the playoffs, Mason proved to be a reliable starting goaltender.
Mason returned to the Nashville crease and posted a respectable 24-11-4 record in 2006-07 and ranked second in the league in save percentage (.925). After Nashville netminder Tomas Vokoun was traded to the Florida Panthers, Mason was left as the starter for the Predators. Mason went on to post a 18-22-6 record and fellow netminder Dan Ellis, who finished with a record thirteen games above .500, took over as the number one goaltender. Mason's stint in Nashville came to an end on June 20, 2008 when the Predators dealt him to the St. Louis Blues for a 4th round draft pick.
In the summer of 2010, as an unrestricted free agent, Mason inked a two-year deal with the Atlanta Thrashers worth a reported $3.7 million dollars.