13+ Feeder Schools
The following schools sent boys to Westminster in 2020:
| Feeder School | Numbers |
| Arnold House School | 3 |
| Devonshire House Preparatory School | 3 |
| Dulwich Prep London | 7 |
| Durston House | 1 |
| Eaton House The Manor | 4 |
| Falcons Preparatory School | 1 |
| Feltonfleet School | 1 |
| Hall School | 8 |
| Harrow International School Hong Kong | 1 |
| Heathside School | 2 |
| Hereward House School | 3 |
| Hill House | 2 |
| Horris Hill | 1 |
| King's College School (Cambridge) | 1 |
| Lochinver House School | 1 |
| Milbourne Lodge School | 1 |
| Newton Prep | 3 |
| North Bridge House | 1 |
| Notting Hill Preparatory School | 1 |
| Orley Farm School | 2 |
| St Anthony’s | 2 |
| St Paul's Cathedral School | 1 |
| Summer Fields | 1 |
| Sussex House | 6 |
| The Beacon School | 1 |
| Thomas’s Battersea | 5 |
| Trevor-Roberts’ | 5 |
| Ursuline Primary School in Lublin | 1 |
| Westminster Under School | 45 |
| Wetherby Prep School | 5 |
| Wetherby Senior School | 1 |