(1) | 42.70 | CBP | Herne Hill Harriers | | 1 FINAL | Sutton Arena | 9 September 2012 |
(2) | 42.80 | | Herne Hill Harriers | | 1 FINAL | Sutton Arena | 8 September 2013 |
(3) | 42.99 | | Herne Hill Harriers 'A' | | 1 FINAL | Carshalton | 3 September 2023 |
(4) | 43.64 | | Herne Hill Harriers 'A' | | 1 HEAT 2 | Carshalton | 3 September 2023 |
(5) | 43.70 | | Woking AC 'A' | | 1 FINAL | Carshalton | 8 September 2019 |
(6) | 43.87 | | Herne Hill Harriers | | 1 FINAL | Carshalton | 14 September 2014 |
(7) | 44.06 | | Hercules Wimbledon AC | | 2 FINAL | Carshalton | 3 September 2023 |
(8) | 44.1 | CBP | Croydon Harriers 'A' | | 1 FINAL | Tooting Bec | 25 April 1987 |
(9) | 44.13 | | Epsom & Ewell Harriers 'A' | | 3 FINAL | Carshalton | 3 September 2023 |
(10) | 44.2 | | Woking AC | | 1 FINAL | Carshalton | 9 September 2018 |
(11) | 44.39 | | Herne Hill Harriers | | 1 FINAL | Carshalton | 13 September 2015 |
(12) | 44.50 | | Hercules Wimbledon AC | | 1 HEAT 1 | Carshalton | 3 September 2023 |
(13) | 44.6 | | Hercules Wimbledon AC | | 1 FINAL | Stompond Lane, Walton | 19 September 1993 |
(14) | 44.64 | | Hercules Wimbledon AC | | 1 FINAL | Carshalton | 12 September 2021 |
(15) | 44.69 | | Hercules Wimbledon AC | | 1 FINAL | Carshalton | 4 September 2022 |
(16) | 44.92 | | Kingston AC & Polytechnic Harriers | | 2 FINAL | Carshalton | 12 September 2021 |
(17) | 45.0 | | Croydon Harriers | | 1 FINAL | Sheerwater, Woking | 22 April 1989 |
(18) | 45.09 | | Epsom & Ewell Harriers 'A' | | 2 HEAT 2 | Carshalton | 3 September 2023 |
(19) | 45.1 | | Epsom & Ewell Harriers 'A' | | 1 FINAL | Ewell Court | 6 May 1972 |
| 45.1 | | Belgrave Harriers | | 1 FINAL | Croydon Arena | 27 April 1985 |
(21) | 45.2y | CBP | Mitcham AC | | 1 FINAL | Battlebridge | 10 June 1961 |
(22) | 45.24 | | Kingston AC & Polytechnic Harriers | | 2 FINAL | Carshalton | 8 September 2019 |
(23) | 45.27 | | Epsom & Ewell Harriers | | 1 FINAL | Carshalton | 11 September 2016 |
(24) | 45.3 | | Epsom & Ewell Harriers | | 1 FINAL | Wimbledon Park | 14 April 1973 |
| 45.3 | | Belgrave Harriers | | 2 FINAL | Stompond Lane, Walton | 19 September 1993 |
(26) | 45.31 | | Herne Hill Harriers 'A' | | 3 FINAL | Carshalton | 8 September 2019 |
(27) | 45.45 | | Sutton & District AC | | 2 FINAL | Carshalton | 13 September 2015 |
(28) | 45.7 | | Epsom & Ewell Harriers 'A' | | 1 HEAT 2 | Motspur Park | 29 April 1978 |
| 45.7 | | Sutton & Cheam Harriers | | 1 FINAL | Motspur Park | 29 April 1978 |
| 45.7 | | Mitcham & Sutton AC | | 1 FINAL | Kingsmeadow Stadium | 22 September 1991 |
(31) | 45.72 | | Sutton & District AC | | 2 FINAL | Carshalton | 11 September 2016 |
(32) | 45.8 | | Wallington High School | | 2 FINAL | Ewell Court | 6 May 1972 |
(33) | 45.89 | | Herne Hill Harriers | | 1 FINAL | Carshalton | 10 September 2017 |
(34) | 45.9y | | Croydon Harriers | | 1 FINAL | Carshalton | 12 May 1956 |
| 45.9 | | Hercules Wimbledon AC | | 1 FINAL | Motspur Park | 30 April 1977 |
| 45.9 | | Hercules Wimbledon AC | | 1 FINAL | Tooting Bec | 26 April 1986 |
(37) | 46.0y | | Tulse Hill School | | 1 FINAL | Wimbledon Park | 9 May 1970 |
| 46.0 | | Sutton & Cheam Harriers | | 1 HEAT 1 | Motspur Park | 29 April 1978 |
(39) | 46.02 | | Hercules Wimbledon AC | | 2 FINAL | Sutton Arena | 8 September 2013 |
(40) | 46.1y | | Ashburton School | | 1 FINAL | Motspur Park | 22 June 1960 |
| 46.1 | | Mitcham AC | | 1 FINAL | Crystal Palace | 23 July 1968 |
| 46.1 | | Hercules Wimbledon AC | | 1 HEAT 2 | Motspur Park | 30 April 1977 |
| 46.1 | | South London Harriers | | 2 FINAL | Motspur Park | 30 April 1977 |
(44) | 46.13 | | Woking AC | | 2 FINAL | Carshalton | 14 September 2014 |
(45) | 46.14 | | Epsom & Ewell Harriers | | 2 FINAL | Carshalton | 4 September 2022 |
(46) | 46.2y | | Belgrave Harriers | | 1 FINAL | Tooting Bec | 19 May 1951 |
| 46.2y | | Ashburton School | | 1 HEAT 2 | Motspur Park | 22 June 1960 |
| 46.2y | | Croydon Harriers | | 1 FINAL | Wimbledon Park | 26 May 1962 |
| 46.2 | | Epsom & Ewell Harriers 'B' | | 2 FINAL | Motspur Park | 29 April 1978 |
| 46.2 | | Croydon Harriers | | 1 FINAL | Motspur Park | 26 April 1980 |
| 46.2 | | Camberley & District AC | | 1 FINAL | Sheerwater, Woking | 21 April 1990 |
| 46.2 | | Herne Hill Harriers | | 2 FINAL | Carshalton | 9 September 2018 |
|
52 performances of 46.20 or better. |