| Lane | Athlete | Yr. | Team | Seed | Note |
|---|---|---|---|---|---|
| 2 | CASTALDI, Jack | FR | Mehlville High School | NT | Unverified: |
| 3 | MCCLURE, Jordan | JR | Webster Groves High School | 1:00.60 | Verified |
| 4 | BEDOYA GARCIA, Juan | JR | Parkway Central High School | 57.99 | Verified |
| 5 | WILSON, Gavin | SR | Webster Groves High School | 58.28 | Verified |
| 6 | WHELEHON, Kyle | SO | Mehlville High School | 1:04.03 | Verified |
| 7 | WIGHTMAN, John | JR | Lindbergh High School | NT | Unverified: |
| Lane | Athlete | Yr. | Team | Seed | Note |
|---|---|---|---|---|---|
| 1 | DRUMMOND, David | SR | Christian Brothers College High | 56.77 | Verified |
| 2 | LORTZ, Kyson | SO | Rolla High School | 55.24 | Verified |
| 3 | BISHOP, Shayn | SO | Ritenour High School | 54.73 | Verified |
| 4 | FRANKS, Garrett | JR | St. Louis University High School | 56.15 | Unverified: |
| 5 | SCHELLMAN, Caleb | JR | Parkway South High School | 54.27 | Verified |
| 6 | BROWN, Stanley | SO | Parkway Central High School | 54.92 | Verified |
| 7 | JORDAN, D'Corey | SO | St. Louis University High School | 53.41 | Verified |
| 8 | LEONARD, David | JR | St. Mary's (St. Louis) High Scho | 57.01 | Verified |
| Lane | Athlete | Yr. | Team | Seed | Note |
|---|---|---|---|---|---|
| 1 | HOTOP, Joshua | JR | Eureka High School | 52.74 | Verified |
| 2 | STINSON, Jagger | SO | Rolla High School | 52.30 | Verified |
| 3 | WATSON, Nathan | SR | Ritenour High School | 51.28 | Verified |
| 4 | MCINTOSH, Donovan | SR | St. Mary's (St. Louis) High Scho | 49.63 | Verified |
| 5 | PETERSON, JACE | SR | Eureka High School | 50.32 | Verified |
| 6 | DUBOSE, Doreon | JR | Christian Brothers College High | 51.66 | Verified |
| 7 | KIM, Nathaniel | SO | Parkway South High School | 52.31 | Verified |
| 8 | THOMAS, Elijah | SR | DeSmet Jesuit High School | 52.84 | Verified |