| Event | Rank | Mark | By | Meet |
| | | National Elites above. State Elites below | | |
| B-400 | 1 | 48.58 | Sholl, Jacob (2015) (Carthage Illini West, IL) | IL 1A Boys State Prelims(IL), 2015-05-28(#1) |
| B-400 | 2 | 49.04 | Rowell, Jordan (2017) (Immaculate Conception, IL) | IL 1A Boys State Finals(IL), 2015-05-30(#2) |
| B-400 | 3 | 49.91 | Stukenberg, Nathan (2015) (Polo Comm, IL) | IL 1A Byron Boys Sectional(IL), 2015-05-22(#1) |
| B-400 | 4 | 49.95 | Gordon, Josh (2016) (Mooseheart, IL) | IL 1A Boys State Prelims(IL), 2015-05-28(#6) |
| B-400 | 5 | 50.02 | Frystak, Nick (2015) (Lake Forest Academy, IL) | Lake County Boys Championships(IL), 2015-05-09(#4) |
| B-400 | 6 | 50.12 | Manges, Jordan (2015) (Illinois School For The Deaf, IL) | IL 1A Boys State Finals(IL), 2015-05-30(#5) |
| B-400 | 7 | 50.37 | Gardewine, Andrew (2015) (St. Anthony, IL) | IL 1A Boys State Finals(IL), 2015-05-30(#6) |
| B-400 | 8 | 50.52 | Vancil, Zach (2017) (West Central, IL) | IL 1A Boys State Prelims(IL), 2015-05-28(#9) |
| B-400 | 9 | 50.62 | Simmons, Kaleb (2016) (Althoff, IL) | IL 1A Chester Boys Sectional(IL), 2015-05-21(#1) |
| B-400 | 10 | 50.89 | Wassell, Kahlil (2017) (New Berlin, IL) | USATF IL Assc JO Championships(IL), 2015-06-28(#10) |
| B-400 | 11 | 50.92 | Pierce, Jackson (2016) (Nashville Comm, IL) | Breese Tri-County Initational(IL), 2015-04-27(#1) |
| B-400 | 12 | 51.03 | Kluck, Cody (2015) (Pearl City, IL) | IL 1A Byron Boys Sectional(IL), 2015-05-22(#2) |
| B-400 | 13 | 51.20 | Labbey, Laken (2015) (Pittsfield, IL) | IL 1A Boys State Prelims(IL), 2015-05-28(#12) |
| B-400 | 14 | 51.28 | Brown, Quintin (2015) (Westmont, IL) | IL 1A Boys State Prelims(IL), 2015-05-28(#13) |
| B-400 | 14 | 51.28 | Silva, Gabriel (2015) (Lebanon, IL) | IL 1A Chester Boys Sectional(IL), 2015-05-21(#2) |
| B-400 | 16 | 51.30 | Peifer, Brett (2015) (Shelbyville, IL) | Tri-County Invitational(IL), 2015-04-21(#1) |
| B-400 | 17 | 51.31 | Rice, Zachary (2016) (Tremont, IL) | Elmwood Trojan Co-Ed Invitational(IL), 2015-04-27(#1) |
| B-400 | 18 | 51.36 | Eastwood, Michael (2017) (Bureau Valley, IL) | IL 1A Boys State Prelims(IL), 2015-05-28(#14) |
| B-400 | 19 | 51.45 | Larimore, Eli (2015) (Tremont, IL) | Elmwood Trojan Co-Ed Invitational(IL), 2015-04-27(#2) |
| B-400 | 20 | 51.51 | Buresh, Ben (2018) (Wethersfield, IL) | IL 1A Farmington Boys Sectional(IL), 2015-05-22(#2) |
| B-400 | 21 | 51.54 | Tomlin, Brad (2015) (ROWVA, IL) | IL 1A Farmington Boys Sectional(IL), 2015-05-22(#3) |
| B-400 | 22 | 51.68 | Porter, Nick (2016) (Paxton-Buckley-Loda, IL) | News-Gazette Honor Roll Meet(IL), 2015-05-18(#1) |
| B-400 | 23 | 51.71 | Howard, Dillon (2017) (Cumberland, IL) | Arthur Invitational(IL), 2015-04-10(#1) |
| B-400 | 24 | 51.73 | Hagene, Kyle (2016) (Sparta, IL) | Buzz Bradley Relays(IL), 2015-04-24(#1) |
| B-400 | 24 | 51.73 | Roundtree, Colby (2015) (Chicago Christian, IL) | Carlin Nalley Invitational(IL), 2015-05-09(#2) |
| B-400 | 26 | 51.83 | Skowronski, Ryan (2018) (Shelbyville, IL) | Shelbyville Boys Open(IL), 2015-04-07(#1) |
| B-400 | 27 | 51.90 | Kirby, Josh (2015) (Peoria Christian, IL) | Dunlap Boys Open(IL), 2015-04-11(#2) |
| B-400 | 28 | 51.91 | Livingston, Blaine (Dwight, IL) | Seneca Irish Invitational(IL), 2015-04-17(#4) |
| B-400 | 28 | 51.91 | Allen, Ryan (2015) (St. Joseph-Ogden, IL) | St. Joseph-Ogden Spartan Classic(IL), 2015-05-01(#1) |
| B-400 | 30 | 51.95 | Heath, Bryan (2015) (Taylor Ridge, IL) | IL 1A Farmington Boys Sectional(IL), 2015-05-22(#4) |
| B-400 | 31 | 51.96 | Labby, Laken (2015) (Pittsfield, IL) | Capital Area Classic(IL), 2015-05-18(#2) |
| B-400 | 32 | 52.03 | Schoonover, Will (2016) (Havana, IL) | IL 1A Tremont Boys Sectional(IL), 2015-05-21(#3) |
| B-400 | 33 | 52.04 | Sewell, Nathan (2016) (Casey-Westfield, IL) | IL 1A Lawrenceville Boys Sectional(IL), 2015-05-21(#2) |
| B-400 | 34 | 52.05 | Ambrose, Nathan (2015) (Winnebago, IL) | Mike Mowen Invitational(IL), 2015-05-08(#1) |
| B-400 | 35 | 52.07 | Bopp, Parker (Robinson, IL) | Robinson Boys Invitational(IL), 2015-04-24(#2) |
| B-400 | 36 | 52.10 | Skinner, Preston (2015) (Shiloh, IL) | IL 1A Boys State Prelims(IL), 2015-05-28(#18) |
| B-400 | 37 | 52.11 | Galaviz, Fedrico (2015) (Arcola, IL) | Monticello Boys Invitational(IL), 2015-04-17(#1) |
| B-400 | 38 | 52.12 | Hemmen, Tyler (2015) (Argenta-Oreana, IL) | Monticello Boys Invitational(IL), 2015-04-17(#2) |
| B-400 | 39 | 52.18 | Gayton, Markese (2017) (Iroquois West, IL) | Herscher Invitational(IL), 2015-05-01(#2) |
| B-400 | 39 | 52.18 | Hasty, Jonathan (2017) (El Paso-Gridley, IL) | IL 1A Bureau Valley Boys Sectional(IL), 2015-05-22(#2) |
| B-400 | 41 | 52.27 | Richardson, Keandre (Sparta, IL) | Murphysboro Boys Invitational(IL), 2015-04-18(#2) |
| B-400 | 42 | 52.28 | Bennett, Michael (2016) (Dwight, IL) | Seneca Irish Invitational(IL), 2015-04-17(#6) |
| B-400 | 42 | 52.28 | Campbell, Antoni (2018) (Aurora Christian, IL) | IL 1A Seneca Boys Sectional(IL), 2015-05-22(#3) |
| B-400 | 44 | 52.31 | Funk, Evan (2015) (Williamsville, IL) | IL 1A Tremont Boys Sectional(IL), 2015-05-21(#4) |
| B-400 | 45 | 52.39 | Bauer, Chris (Urbana University, IL) | St. Joseph-Ogden Spartan Classic(IL), 2015-05-01(#2) |
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| | | See more performances for B-400 | | |
