(1) | 49.43 | CBP | Tyri Donovan | (Windsor, Slough, Eton & Hounslow AC) | 1 FINAL | Kingsmeadow Stadium | 12 May 2024 |
(2) | 49.97 | CBP | Jacob Paul | (Windsor, Slough, Eton & Hounslow AC) | 1 FINAL | Kingsmeadow Stadium | 15 May 2022 |
(3) | 51.25 | CBP | Tyri Donovan | (Windsor, Slough, Eton & Hounslow AC) | 1 FINAL | Kingsmeadow Stadium | 1 August 2021 |
| 51.25 | | Jacob Paul | (Windsor, Slough, Eton & Hounslow AC) | 1 FINAL | Kingsmeadow Stadium | 14 May 2023 |
(5) | 51.33 | | Jacob Paul | (Windsor, Slough, Eton & Hounslow AC) | 2 FINAL | Kingsmeadow Stadium | 12 May 2024 |
(6) | 52.66 | CBP | Austin Ferns | (Hercules Wimbledon AC) | 1 FINAL | Kingsmeadow Stadium | 11 May 2008 |
(7) | 52.7y | CBP | Robin Woodland | (Hercules AC) | 1 FINAL | Motspur Park | 30 May 1964 |
| 52.7 | CBP | Richard Holt | (Blackheath Harriers) | 1 FINAL | Croydon Arena | 14 May 1995 |
(9) | 52.9y | | Robin Woodland | (Hercules AC) | 1 FINAL | Motspur Park | 21 May 1966 |
| 52.9 | | George Sandy | (Hercules Wimbledon AC) | 1 FINAL | Wimbledon Park | 10 May 1997 |
(11) | 52.99 | | Noel Levy | (Belgrave Harriers) | 1 FINAL | Kingsmeadow Stadium | 12 May 2002 |
(12) | 53.0 | CBP | David Haizelden | (Croydon Harriers) | 1 FINAL | Sheerwater, Woking | 24 April 1988 |
(13) | 53.1y | CBP | Robin Woodland | (Hercules AC) | 1 FINAL | Motspur Park | 3 June 1961 |
| 53.1y | | Robin Woodland | (Hercules AC) | 1 FINAL | Motspur Park | 20 May 1967 |
(15) | 53.11 | | Andy Clements | (Windsor, Slough, Eton & Hounslow AC) | 1 FINAL | Kingsmeadow Stadium | 26 May 2013 |
(16) | 53.23 | | Austin Ferns | (Hercules Wimbledon AC) | 1 FINAL | Kingsmeadow Stadium | 13 May 2007 |
(17) | 53.4 | | Glenn Gray | (Puma Thames Valley Harriers) | 1 FINAL | Kingsmeadow Stadium | 8 May 1999 |
(18) | 53.44 | | Blade Ashby | (Herne Hill Harriers) | 1 FINAL | Kingsmeadow Stadium | 24 May 2015 |
(19) | 53.5y | | Ian Morgan | (Guy's Hospital ) | 2 FINAL | Motspur Park | 20 May 1967 |
(20) | 53.53 | | William Ritchie-Moulin | (Birchfield Harriers) | 2 FINAL | Kingsmeadow Stadium | 14 May 2023 |
(21) | 53.6y | | Robin Woodland | (Hercules AC) | 1 FINAL | Motspur Park | 25 May 1963 |
| 53.6 | CBP | Maurice Evans | (Shaftesbury Harriers) | 1 FINAL | Tooting Bec | 26 April 1987 |
(23) | 53.7 | | Tony Collins | (Herne Hill Harriers) | 1 FINAL | Motspur Park | 5 June 1971 |
(24) | 53.8 | | S Gray | (Thames Valley Harriers) | 2 FINAL | Wimbledon Park | 10 May 1997 |
(25) | 53.82 | | Luke Dronfield | (Blackheath & Bromley Harriers AC) | 3 FINAL | Kingsmeadow Stadium | 12 May 2024 |
(26) | 53.9y | | Ian Morgan | (Walton AC / Guy's Hospital ) | 1 FINAL | Motspur Park | 8 June 1968 |
| 53.9 | | Maurice Evans | (Shaftesbury Harriers) | 1 HEAT 1 | Tooting Bec | 26 April 1987 |
(28) | 54.0 | | Tony Collins | (Herne Hill Harriers) | 1 FINAL | Motspur Park | 7 June 1969 |
| 54.0 | | Maurice Evans | (Shaftesbury Harriers) | 1 FINAL | Tooting Bec | 27 April 1986 |
(30) | 54.08 | | Tom Parry | (Kingston AC & Polytechnic Harriers) | 2 FINAL | Kingsmeadow Stadium | 24 May 2015 |
(31) | 54.1 | | Mike Whittingham | (Herne Hill Harriers) | 1 FINAL | Motspur Park | 18 May 1974 |
(32) | 54.11 | | Andrew Ajube | (Thames Valley Harriers) | 4 FINAL | Kingsmeadow Stadium | 12 May 2024 |
(33) | 54.32 | | Andy Clements | (Windsor, Slough, Eton & Hounslow AC) | 1 FINAL | Kingsmeadow Stadium | 13 May 2012 |
(34) | 54.49 | | Austin Ferns | (Hercules Wimbledon AC) | 1 FINAL | Kingsmeadow Stadium | 15 May 2005 |
(35) | 54.5 | | Mark Purser | (Croydon Harriers) | 1 FINAL | Croydon Arena | 12 May 1996 |
(36) | 54.6y | | Ollie Baggott | (Surrey AC) | 2 FINAL | Motspur Park | 8 June 1968 |
| 54.6 | | Glenn Gray | (Thames Valley Harriers) | 1 FINAL | Croydon Arena | 13 May 2000 |
(38) | 54.61 | | Andrew Ajube | (Thames Valley Harriers) | 2 FINAL | Kingsmeadow Stadium | 1 August 2021 |
(39) | 54.7y | | Robin Woodland | (Hercules AC) | 1 FINAL | Motspur Park | 2 June 1962 |
| 54.7 | | Glenn Gray | (Thames Valley Harriers) | 2 FINAL | Croydon Arena | 12 May 1996 |
(41) | 54.74 | | Andy Clements | (Windsor, Slough, Eton & Hounslow AC) | 1 FINAL | Kingsmeadow Stadium | 15 May 2011 |
(42) | 54.8 | | Mark Purser | (Croydon Harriers) | 2 FINAL | Croydon Arena | 14 May 1995 |
(43) | 54.9y | | Ian Morgan | (Woking AC / Guy's Hospital ) | 2 FINAL | Motspur Park | 30 May 1964 |
| 54.9y | | George Tymms | (Surrey AC) | 1 FINAL | Motspur Park | 29 May 1965 |
(45) | 54.92 | | James Parker | (Epsom & Ewell Harriers) | 2 FINAL | Kingsmeadow Stadium | 12 May 2002 |
| 54.92 | | Derek Paisley | (Blackheath & Bromley Harriers AC) | 2 FINAL | Kingsmeadow Stadium | 11 May 2008 |
| 54.92 | | Andrew Ajube | (Thames Valley Harriers) | 2 FINAL | Kingsmeadow Stadium | 15 May 2022 |
(48) | 54.98 | | Derek Paisley | (Blackheath & Bromley Harriers AC) | 1 FINAL | Kingsmeadow Stadium | 10 May 2009 |
(49) | 55.1 | | Steve Johnson | (Epsom & Ewell Harriers) | 1 FINAL | Motspur Park | 15 May 1976 |
(50) | 55.2 | | Keith Andrew | (Hercules Wimbledon AC) | 2 FINAL | Tooting Bec | 27 April 1986 |
| 55.2 | | Jonathan Owen | (Hercules Wimbledon AC) | 2 FINAL | Tooting Bec | 26 April 1987 |
|
51 performances of 55.20 or better. |