* The Arizona Coyotes forfeited their first-round pick (No. 11) because of a violation of the League's Combine Testing Policy. Official records will show the Blues picking at No. 17, but they will actually be making the 16th pick.
- The Blues' traded their second-round pick in the 2021 NHL Draft to the Buffalo Sabres along with Vladimir Sobotka, Patrik Berglund, Tage Thompson and a conditional draft pick in the deal that brought Ryan O'Reilly to St. Louis in 2018. Buffalo eventually traded the pick to Vegas, who then sent it to Los Angeles in a deal that brought Alec Martinez to the Golden Knights.
- The Blues' fourth-round pick (No. 113 overall) was sent to the Montreal Canadiens in a trade that brought Marco Scandella to the Blues on Feb. 18, 2020.
- At the 2020 NHL Draft, the Blues traded a seventh-round pick (No. 203 overall) to the Detroit Red Wings in exchange for their seventh-round pick in 2021 (No. 198).
- The Blues' original seventh-round pick in 2021 (No. 209) belongs to the Carolina Hurricanes. The pick was acquired by Carolina, along with Joel Edmundson and Dominik Bokk, in the deal that brought Justin Faulk and a fifth-round pick in 2020 to the Blues on Sept. 24, 2019.