Alexander Steen was born March 1, 1984 in Winnipeg, Manitoba. The first round, 24th overall selection of the Toronto Maple Leafs in the 2002 NHL Entry Draft, Steen, who honed his skills in the Swedish Jr. and Elite Leagues is the son of former Winnipeg Jet Thomas Steen.
An offensively gifted forward, Steen suited up for Goteburg, Frolunda and Modo before making his North American and NHL debut with Toronto during the 2005-06 season. Over the next three-plus seasons in Toronto, Steen never produced more than the 18 goals he had in his rookie season. The former first overall draft pick had just four points early into the 2008-09 season and Toronto Maple Leafs General Manager Cliff Fletcher decided to send him to St. Louis in a multi-player trade..
Steen would break out offensively during the 2013-14 season. Appearing in 68 games for the Blues, he reached the 30-goal plateau for the first time in his career, finishing the year with 33 goals and 62 points
In 2014-15, Steen would establish a new career-high in points with 64. Appearing in 74 games, he found the back of the net 24 times and added 40 assists, which was also a career-high. Steen was limited to just 67 games during the 2015-16 season, but still managed to contribute 17 goals and 35 assists.
On the international stage, Steen twice represented Sweden at the World Junior Championship and again during the 2014 Winter Olympics where he helped the team to a silver medal.