Mike Smith was born March 22, 1982 in Kingston, Ontario. The Stars' fifth round selection, 161st overall in the 2001 NHL Entry Draft, Smith honed his skills with the OHL's Kingston Frontenacs, and Sudbury Wolves.
Smith began his junior hockey career with his hometown Kingston Frontenacs of the Ontario Hockey League. He was dealt from Kingston after only 18 games to the Sudbury Wolves in 2001. In Subury Smith posted a solid 22-13-7 record and a sparkling 2.52 GAA in only his second full year of junior hockey. After his final year in the OHL, Smith made the leap into the pro ranks and split his 2002-03 season between Lexington of the ECHL and Utah of the AHL. The following year he shared his role between the pipes with Josh Harding in the Houston Aero crease. Following a respectable 19-17-3 with the Iowa Stars in 2005-06, Smith started 50 games with the Iowa Stars and earned the starters position.
The ensuing summer, Smith underwent shoulder surgery to repair an injury he suffered during his 2005-2006 season in Iowa. He made a full recovery and attended the Dallas Stars' training camp in the fall of 2006, winning the role as the Stars' backup goaltender. After signing a two-year contract with the Stars, Smith went on to post a 12-5-2 in his third season of professional hockey. Later that year he was named to the 2006-07 NHL All-Rookie Team. The following season Smith went 12-9 in 21 starts with the Stars and posted a respectable 2.46 G.A.A. However, at the NHL trading deadline Smith was dealt to the Tampa Bay Lightning with Jeff Halpern and Jussi Jokinen in exchange for Brad Richard goaltender Johan Holmqvist.
The Lightning struggled during Smith's time with the club. Though he put up respectable numbers including a 2.62 goals-against-average in the 2008-09 season, the team failed to make the playoffs.
On January 1, 2011, the Lightning acquired goaltender Dwayne Roloson from the New York Islanders. The move forced Smith into a backup role behind the veteran Roloson.
On February 2, 2011 Smith was assigned to the Norfolk Admirals of the American Hockey League, though he would be re-called by Tampa to serve as the backup goaltender during the 2011 playoffs.
On July 1, 2011, Smith signed a deal with the Phoenix Coyotes as an unrestricted free agent. As a member of the Coyotes Smith would begin to establish himself as on of the league's premier puck-stoppers. In the 2011-12 season he would record 38 wins an impressive goals against average of just 2.21.
On the international stage Smith would represent Canada at the 2013 World Hockey Championship. In four games he would notch two wins and a miniscule 1.65 goals against average.
In 2014 Smith was once again called upon to represent Canada. This time at the Olympic Winter Games held in Sochi, Russia. He and his teammates would return as gold medal winners, the second consecutive Olympic victory for Canada.