|
400 Metres (Standard: 55.00) |
| 49.11 | | Jack Dickson | Kingston AC & Polytechnic Harriers | Kingston | 3 Jul | | |
| 49.64 | | Henry Fisher | Blackheath & Bromley Harriers AC | Stratford (CT) | 13 Jun | | |
| 49.85 | | Joshua Pearson | Windsor, Slough, Eton & Hounslow AC | Harrow | 13 May | | |
| 50.8 | | Ethan Dray | Walton AC | Walton | 5 Sep | | |
| 50.92 | | Drew Burridge | Blackheath & Bromley Harriers AC | Gillingham | 3 May | | |
| 52.18 | | Jacob Harrison | South London Harriers | Plymouth | 14 Aug | | |
| 52.29 | | George Rees | Kingston AC & Polytechnic Harriers | Kingston | 3 Jul | | |
| 52.41 | | Jake Osorio | Herne Hill Harriers | Hendon | 21 Aug | | |
| 52.5 | | Memphis Ayoade | Herne Hill Harriers | Battersea Park | 20 Jun | | |
| 52.8 | | Jacob Alley | Herne Hill Harriers | Battersea Park | 20 Jun | | |
| 52.9 | | George Asprey | Aldershot, Farnham & District AC | Lee Valley | 26 Jun | | |
| 53.3 | | Alex Dunn | Sutton & District AC | Carshalton | 14 Aug | | |
| 53.43 | | Benjamin Harrison | South London Harriers | Plymouth | 14 Aug | | |
| 53.59 | | Theo Cheshire | Woking AC | Southampton | 16 May | | |
| 54.0 | | Oli Hector | Herne Hill Harriers | Kingston | 25 Jul | | |
| 54.20 | | Max Dickson | Kingston AC & Polytechnic Harriers | Chelmsford | 6 Jun | | |
| 54.69 | | Michael Webb-Bourne | Kingston AC & Polytechnic Harriers | Carshalton | 27 Jun | | |
| 54.7 | | Cameron Enser | Bracknell AC | Aldershot | 14 Aug | | |