| Date | Player | Position | Transaction |
|---|---|---|---|
| May 22 | Rokevious Watkins | LOG | Suspended by St. Louis (1 game (NFL Substance Abuse Policy)) |
| May 21 | Terrell Brown | T | Signed by St. Louis |
| May 20 | Zach Potter | TE | Signed/unrest FA |
| May 16 | Andrew Helmick | WR | Signed by St. Louis |
| May 13 | Sean Hooey | T | Signed by St. Louis |
| May 13 | Tim Jenkins | QB | Signed by St. Louis |
| May 13 | Joseph LeBeau | LB | Signed by St. Louis |
| May 13 | Andre Martin | CB | Signed by St. Louis |
| May 13 | Scott Pillar | WR | Signed by St. Louis |
| May 13 | Don Unamba | CB | Signed by St. Louis |
| May 9 | Cody Davis | SS | Signed by St. Louis |
| May 9 | Garrett Goebel | LDT | Signed by St. Louis |
| May 9 | Jorgen Hus | LS | Signed by St. Louis |
| May 9 | Robert Steeples | LCB | Signed by St. Louis |
| May 9 | Eric Stevens | RB | Signed by St. Louis |
| May 9 | C.J. Akins | WR | Signed by St. Louis |
| May 9 | Daren Bates | MLB | Signed by St. Louis |
| May 9 | Benny Cunningham | RB | Signed by St. Louis |
| May 9 | Philip Lutzenkirchen | TE | Signed by St. Louis |
| May 9 | Cannon Smith | FS | Signed by St. Louis |
| May 9 | Brett Baer | KFG/KKO | Signed by St. Louis |
| May 9 | Emory Blake | WR | Signed by St. Louis |
| May 9 | Al Lapuaho | RDT | Signed by St. Louis |
| May 9 | Jonathan Stewart | RLB | Signed by St. Louis |
| May 9 | C.J. Akins | WR | Signed by St. Louis |
| May 9 | Ray-Ray Armstrong | RLB | Signed by St. Louis |
| May 9 | Braden Brown | LOT | Signed by St. Louis |
| May 9 | Gerald Rivers | RDE | Signed by St. Louis |
| May 9 | Kevin Saia | LOG | Signed by St. Louis |
| May 9 | Phillip Steward | LLB | Signed by St. Louis |
| May 9 | Drew Thomas | LCB | Signed by St. Louis |
| May 9 | R.J. Washington | RDE | Signed by St. Louis |
| May 9 | Darren Woodard | RCB | Signed by St. Louis |
| May 6 | Tim Barnes | C | Re-signed/excl. FA by St. Louis |
| May 2 | Al Harris | CB | Signed by St. Louis (One-day contract) |
| May 1 | Mike McNeill | TE | Re-signed/excl. FA by St. Louis |