Steen ends a 15-year NHL career that began with the Toronto Maple Leafs and ended with over 11 seasons in St. Louis, including the title-winning run in 2019.
According to the Blues, Steen has degenerative herniated disks in his spine, which allowed him to play in only four of St. Louis' nine postseason games this year.
"This has been an emotional process," Steen told the team website. "But as I look back on my years in hockey, I would like to thank our organization, our city, our fans and my teammates as I am so proud of all the teams I was part of."
Steen posted 245 goals and 377 assists in 1,018 career NHL games.