The younger brother of former NHL forward Anthony Stewart, Chris was selected by the Colorado Avalanche at No. 18 in the 2006 NHL Draft. With a hard shot, good speed and a strong work ethic, Stewart went from a fourth-line player to a feared scorer.

Stewart stopped playing hockey in favor of football at 14 but resumed playing at 16 at the urging of Anthony, who arranged a tryout with his junior team, Kingston of the Ontario Hockey League. Chris made the team and eventually became captain, just like his brother.

Stewart made his NHL debut Dec. 5, 2008 against the Dallas Stars. Four days later, he got his first two NHL points, on a shorthanded goal and an assist in Colorado's 6-1 win against the Los Angeles Kings. Stewart finished the season with 11 goals and 19 points in 53 games while averaging 12:20 of ice time.

In 2009-10, Stewart led the Avalanche with 28 goals in 77 games, was second with 64 points and ranked 10th in the NHL with 25 even-strength goals. On March 6, 2010, Stewart got his first NHL hat trick and had an assist in Colorado's 7-3 win against the St. Louis Blues. He was leading Colorado with 11 goals when he broke his left hand on Nov. 27, 2010.

The injury sidelined Stewart until Jan. 14, 2011, and he was traded to the Blues on Feb. 19. That night he scored two power-play goals in his Blues debut in a 9-3 win against the Anaheim Ducks. He finished the season with 28 goals in 62 games, including 15 goals and 23 points in 26 games with the Blues.

Stewart spent four seasons in St. Louis before he was traded to the Buffalo Sabres on Feb. 28, 2014. The Sabres traded Stewart to the Minnesota Wild on March 2, 2015 and, after the season, Stewart signed as a free agent with Anaheim. On July 1, 2016, he signed a two-year contract to return to the Wild.

Stewart was claimed off waivers by the Calgary Flames on Feb. 26, 2018 and played seven games. He signed a professional tryout contract with the Philadelphia Flyers on July 17, 2019 and signed a one-year contract Oct. 15, 2019.