EVENT 306 Open/Male 100m Butterfly - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 2 | 1 | Daniil Obuhov | 11 | Braunstone | 2:01.59 |
| 3 | 3 | David Ursachi | 11 | Co Leicester | 1:59.80 |
| 4 | 5 | Callum Taylor | 13 | Northampton | 1:45.00 |
| 5 | 4 | Ethan Woodward | 13 | Northampton | 1:49.37 |
| 6 | 2 | Victor Puscasu | 11 | Northampton | 2:00.00 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 7 | Andrei Obuhov | 13 | Braunstone | 1:32.09 |
| 2 | 9 | Fraser Manley | 12 | Repton | 1:29.50 |
| 3 | 11 | Isaac Ebanks | 14 | Derby Excel | 1:21.22 |
| 4 | 13 | David Bielawski | 15 | Northampton | 1:15.40 |
| 5 | 12 | Kevin Varga | 11 | Co Leicester | 1:20.42 |
| 6 | 10 | V Bramley - Howell | 14 | Leic Peng | 1:21.48 |
| 7 | 8 | James Oscroft | 11 | Northampton | 1:31.30 |
| 8 | 6 | Jonathan Gbyliczek | 12 | Co Lincoln P | 1:40.02 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 15 | Riley Woodward | 15 | Northampton | 1:14.20 |
| 2 | 17 | George Howard | 12 | Co Leicester | 1:13.11 |
| 3 | 19 | Lawrence Chapman | 16 | Worksop | 1:12.43 |
| 4 | 21 | Jack Smith | 14 | Co Leicester | 1:09.98 |
| 5 | 20 | Emerson-Blu Gupwell | 14 | Co Leicester | 1:11.90 |
| 6 | 18 | Gabriel Corbett | 14 | Leic Peng | 1:12.52 |
| 7 | 16 | Kais Alhijazi | 13 | Co Leicester | 1:13.19 |
| 8 | 14 | Jacson Crabb | 13 | Co Leicester | 1:14.63 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 23 | Charlie Wheeler-Kaye | 15 | Worksop | 1:07.78 |
| 2 | 25 | Thomas Blacklaws | 16 | Leic Sharks | 1:03.94 |
| 3 | 27 | Cody Ingram | 18 | Bo Barnsley | 1:01.64 |
| 4 | 29 | James Frost | 17 | Newport | 1:01.34 |
| 5 | 28 | Kieran Flint | 26 | Market Har | 1:01.50 |
| 6 | 26 | Daniel Harris | 17 | Co Leicester | 1:02.65 |
| 7 | 24 | David Bucur | 16 | Worksop | 1:06.39 |
| 8 | 22 | William Oxley | 14 | Co Leicester | 1:08.70 |