| Rank | Time | Student | Grade | School | Year | |
| 1 | 46.30 | Justin Robinson | | Hazelwood West | 2018 | Class 5 |
| 2 | 46.81 | Domenik Peterson | | Jefferson City | 2003 | Class 4 |
| 3 | 46.82 | Quincy Hall | | Raytown South | 2016 | Prelims |
| 4 | 46.93 | Justin Robinson | | Hazelwood West | 2017 | Class 5 |
| 5 | 46.98 | Quincy Hall | | Raytown South | 2015 | |
| 6 | 47.01 | Charles Jones | | Cardinal Ritter | 2014 | Class 3 |
| 7 | 47.07 | Marcus Davis | | Hazelwood Central | 2014 | Class 4 |
| 8 | 47.21 | Isaiah Cole | | Hazelwood West | 2016 | Class 5 |
| 9 | 47.37 | Edwin Harris | | Knob Noster | 1997 | Class 3 |
| 10 | 47.75 | Herbert Johnson | | Fulton | 1981 | Class 3 |
| 10 | 47.75 | Tellis D Smith | | Sumner | 2010 | Class 3 |
| 12 | 48.00 | Nylo Ezekiel Clarke | | Park Hill South | 2016 | Class 5 |
| 13 | 48.14 | Jermaine Christopher Holt | | Parkway North | 2016 | Class 5 |
| 14 | 48.17 | Issam Asinga | | Principia | 2020 | Class 2 |
| 15 | 48.44 | Tony Hilliard | | Priory | 1981 | Class 2 (48.2h) |
| 16 | 48.47 | Brandon Campbell | | Cardinal Ritter | 1998 | Class 2 |
| 16 | 48.47 | Marcus Taylor | | Maplewood-Richmond Hts. | 2011 | Class 2 |
| 18 | 49.15 | Cade Nold | Jr | Dora | 2023 | Class 1 |
| 19 | 49.30 | Zac Breitkreutz | | Lutheran (Kansas City) | 2016 | Class 1 |
| 20 | 49.63 | Dominick T Fleeks | | Stewartsville | 2013 | Class 1 |
| 21 | 49.66 | Brandon Etzold | | Saxony Lutheran | 2007 | Class 1 |