Blues general manager Doug Armstrong announced on Wednesday that Brodeur has signed a three-year deal to be the team's assistant GM.
Brodeur played seven games for St. Louis last season, retiring Jan. 29 to become a senior adviser to Armstrong.
"It's a great opportunity," Brodeur told the Blues website. "I got a little taste of it last season and really enjoyed being around Doug and the organization. It's a good fit for me, and it works out well. I'm really happy about it.
"I want to put the work in. I want to learn how everything works, to learn the organization. I'm committed to do the work and do as much as I can to help the team get better. It's a good fit for me to be able to learn what I have to learn."
The 43-year-old Brodeur played 21 seasons with the New Jersey Devils before his brief time with the Blues.
He won the Stanley Cup three times and the Vezina Trophy four times with New Jersey, and retired as the NHL's all-time regular-season leader in wins (691), shutouts (125), games played (1,266) and minutes played (74,438). Brodeur is also first all time in Stanley Cup Playoff starts (204) and shutouts (24), and second in wins (113).