EVENT 203 Open/Male 100m Butterfly - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 3 | 1 | Felix MAYER | 10 | Kettering | 2:00.94 |
| 4 | 3 | Spencer CROSS | 10 | Melton M'bry | 1:48.19 |
| 5 | 2 | Henry RAITT | 11 | Corby | 1:55.00 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 2 | 5 | Harry LANGSTONE | 13 | Kettering | 1:36.24 |
| 3 | 7 | George BROTHERSTON | 15 | Wellingboro | 1:32.80 |
| 4 | 9 | Alex LAWRENCE | 12 | Daventry | 1:30.30 |
| 5 | 8 | Ianis MANTOC | 11 | Corby | 1:31.83 |
| 6 | 6 | Grayson WATFORD | 11 | Wellingboro | 1:34.74 |
| 7 | 4 | Noah REDWOOD-MOORE | 12 | Melton M'bry | 1:40.70 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 11 | Oscar CUTMORE | 11 | Corby | 1:28.28 |
| 2 | 13 | Finley STEVENSON | 14 | Corby | 1:25.07 |
| 3 | 15 | George YEOMANS | 14 | Rushden | 1:22.22 |
| 4 | 17 | Matthew KEMP | 15 | Wellingboro | 1:20.00 |
| 5 | 16 | Archie DICKINS | 12 | Hinckley | 1:22.01 |
| 6 | 14 | Eric BUTANS | 14 | Corby | 1:22.60 |
| 7 | 12 | George HATWOOD | 13 | Wellingboro | 1:28.00 |
| 8 | 10 | Jesunefe ABEKE | 15 | Corby | 1:29.87 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 19 | Ruben HICKMAN | 18 | Kettering | 1:15.72 |
| 2 | 21 | Ethan ILENKIW | 16 | Market Har | 1:14.10 |
| 3 | 23 | Wojciech WALACH | 14 | Corby | 1:13.00 |
| 4 | 25 | Alexandru IERINA | 15 | Kettering | 1:10.00 |
| 5 | 24 | Ollie DOVEY | 15 | Corby | 1:10.25 |
| 6 | 22 | Ronnie BOOKER | 16 | Wellingboro | 1:13.84 |
| 7 | 20 | Yogi PATEMAN | 17 | Wellingboro | 1:14.80 |
| 8 | 18 | Aidan PENNEY | 15 | Wellingboro | 1:18.00 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 27 | Curtis MINNEY | 20 | Kettering | 1:01.20 |
| 2 | 29 | Daniel DOYLE | 17 | Kettering | 59.70 |
| 3 | 31 | Ryan COLES | 20 | Daventry | 57.95 |
| 4 | 33 | Louis MITCHELL | 24 | Corby | 55.90 |
| 5 | 32 | M VASCONCELLOS-BLANCH | 17 | Rushden | 57.00 |
| 6 | 30 | Sam BRYLKA | 16 | Corby | 59.41 |
| 7 | 28 | Mark KHAMETOV | 17 | Kettering | 1:00.00 |
| 8 | 26 | Elliott BARKER | 18 | Nene Valley | 1:05.94 |