Open/Male - Long Course - 400m Individual Medley - Aberystwyth and District Swimmin - All Time - Open Age Group
| Rank | Name | Ranked Club | YoB | Meet | Date | Time |
|---|---|---|---|---|---|---|
| 1 | Joshua Nathanie Harries | Aberystwyth | 92 | Swim Wales Winter Open, Swansea | 24/11/07 | 4:50.33 |
| 2 | Sam Middleton | Aberystwyth | 89 | National Youth & Open 2006, Sheffield | 06/08/06 | 4:53.31 |
| 3 | James Raw | Leic Sharks | 07 | Swim Wales National Championships 2022, Swansea | 15/04/22 | 4:59.51 |
| 4 | Steffan Herdman | Aberystwyth | 99 | Swim Wales Summer Nationals, Swansea | 05/08/16 | 5:05.27 |
| 5 | Tomos Watson | Aberystwyth | 97 | 3 Towers Open Meet, Millfield | 26/10/13 | 5:34.49 |
| 6 | Sion Owen | Aberystwyth | 94 | Welsh Age & Youth Champs, Swansea | 20/03/08 | 5:34.57 |
| 7 | James Payne | Aberystwyth | 01 | Swim Wales Legends Meet, Swansea | 17/09/16 | 5:36.93 |
| 8 | Morgan Evans | Aberystwyth | 01 | City of Cardiff Tiger Bay Meet, Cardiff | 21/03/15 | 6:03.38 |
| 9 | Joseph Gorman | Aberystwyth | 04 | Swim Wales Legends Meet, Swansea | 16/09/17 | 6:09.39 |
| 10 | Benjamin Jones | Aberystwyth | 96 | Welsh Summer Nationals, Swansea | 02/08/07 | 6:40.63 |
| 11 | James Michael | Aberystwyth | 00 | 3 Towers Open Meet, Millfield School | 27/10/12 | 6:48.62 |
| 12 | Jamie Owen | Aberystwyth | 95 | Welsh Summer Nationals, Swansea | 02/08/07 | 6:53.01 |
| 13 | 7:29.11 |