| Time | Date | Name | Meet |
|---|---|---|---|
| 44.58 | Feb. 27, 2015 | Murphy McQuet | 15 Illinois Boys State Championships |
| 44.66 | Feb. 24, 2012 | Max Grodecki | 12 Illinois Boys High School State Championships |
| 45.17 | March 1, 2011 | Max Grodecki | 11 Illinois Boys High School Best Times |
| 46.49 | Feb. 26, 2010 | Max Grodecki | Illinois Boys High School Championships |
| 47.09 | Feb. 24, 2006 | Stephen Pendleton | Illinois State High School Championships |
| 47.57 | Feb. 27, 2004 | Zach Siegel | IHSA Boys State Championships |
