| Tue15 Jun2021 |
| | 09:00 | Tennis: Y8 Girls' Inter-House | Kings' Tennis Courts |
| | 10:40 | Cricket: Y9 Boys' Inter-House | Chesham Road Playing Fields - HP4 3AE |
| | 10:40 | Tennis: Y9 Girls' Inter-House | Kings' Tennis Courts |
|  | 16:30 | Tennis U15B, U13A | v St Albans High School for Girls | H |
| |
| Wed16 Jun2021 |
|  | 14:30 | Cricket U13B, U13D | v York House School | H |
| | 15:00 | Cricket U13A, U12A | v Merchant Taylors' School, Northwood | A |
| | 15:00 | Cricket U13C | v Merchant Taylors' School, Northwood | H |
| |
| Thu17 Jun2021 |
| | 10:40 | Tennis: Y10 Boys' Inter-House | Castle Astro |
| | 10:40 | Tennis: Y10 Girls' Inter-House | Kings' Tennis Courts |
|  | 14:30 | Football 1st XI | v Haileybury | A |
| | 16:30 | Tennis U13A | v Watford Grammar School for Boys | H |
| | 16:45 | Tennis U15A | v St Albans School | A |
| |
| Fri18 Jun2021 |
| | 09:00 | Year 8 Boys' Sports Day | Kitchener's Field - HP4 1HE |
| | 10:40 | Year 7 Boys' Sports Day | Kitchener's Field - HP4 1HE |
| | 13:30 | Cricket U14B | v DAOS U14 T10 Cricket Festival | A |
| | 14:30 | Cricket U14A, U14B, U14C | v Dr Challoner's Grammar School | H |
| |
| Sat19 Jun2021 |
| | 08:45 | Fives: Y9 Inter-House | Castle & Prep Courts |
| | 09:00 | Cricket U13C, U13D, U12C, U12D | v Internal Game | H |
| | 09:30 | Cricket U14A, U14B, U12A, U12B | v St George's Weybridge | A |
| | 09:30 | Cricket U13A, U13B | v St George's Weybridge | H |
| | 11:30 | Cricket 1st XI | v Bedford School | A |
| | 13:00 | Cricket U13C, U12C | v Bedford Preparatory School | A |
| | 13:30 | Cricket U15A, U15B, U15C | v Bedford School | A |
| | 13:45 | Cricket U13A, U13B, U12A, U12B | v Bedford Preparatory School | H |
| | 14:15 | Cricket 2nd XI, 3rd XI, U14A, U14B, U14C | v Bedford School | H |
| |
| Mon21 Jun2021 |
| | 14:30 | Cricket U15B | v Chesham Grammar School | H |
| | 16:15 | Cricket | v Mill Hill & Belmont Schools | A |
| | 16:30 | Tennis U15A, U15B | v The Royal Masonic School for Girls | A |
| |
| Tue22 Jun2021 |
| | 10:40 | Cricket: Y9 Boys' Inter-House (Round 2) | Chesham Road Playing Fields - HP4 3AE |
| | 14:30 | Cricket 1st XI, 3rd XI | v Aylesbury Grammar School | H |
| |
| Wed23 Jun2021 |
|  | 09:00 | Athletics | ESAA Track and Field Cup Rd 1 | Woodside Stadium, Watford, WD25 7HH |
| | 14:00 | Cricket U13D | v Ashlyns School | H |
| | 14:30 | Cricket U13A, U13B, U13C, U13D, U13E, U13F | v Bishop's Stortford College | H |
| | 14:30 | Cricket U13A | v Dr Challoner's Grammar School | A |
| | 14:30 | Cricket U13C, U12A, U12B, U12C | v Dr Challoner's Grammar School | H |
| |
| Thu24 Jun2021 |
| | 10:40 | Year 10 Boys' Sports Day | Chesham Road Playing Fields - HP4 3AE |
| | 11:30 | Cricket 2nd XI | v Oakham School | H |
| | 16:45 | Tennis U15A, U13A | v Haberdashers' Aske's School for Girls | H |
| |
| Fri25 Jun2021 |
| | 09:00 | Tennis: Y8 Boys' Inter-House | Castle Astro |
| | 10:40 | Tennis: Y7 Boys' Inter-House | Castle Astro |
| | 14:30 | Cricket U14B | v Chesham Grammar School | H |
| | 14:40 | Year 9 Girls' Sports Day | Kitchener's Field - HP4 1HE |
| |
| Sat26 Jun2021 |
| | 08:45 | Fives: Year 5 Inter-House (Mixed) | Castle Courts |
| | 09:00 | Cricket: Y7 & 8 Girls' Inter-House | Haslam Playing Fields - HP4 3NG |
| | 09:30 | Cricket: Y7 Boys' Inter-House | Chesham Road Playing Fields - HP4 3AE |
| | 11:30 | Cricket 1st XI | v Stowe School | A |
| | 12:30 | Fives: Y6 Inter-House (Boys) | Castle Courts |
| | 12:30 | Fives: Y6 Inter-House (Girls) | Prep Courts |
| | 13:00 | Cricket: Y8 Boys' Inter-House | Kitchener's Field - HP4 1HE & Haslam Playing Fields - HP4 3NG |
| | 14:00 | Cricket 3rd XI, U15A, U15B, U15C | v Stowe School | A |
| | 14:00 | Cricket 2nd XI, U14A, U14B, U14C, U14D | v Stowe School | H |
| |
| Sun27 Jun2021 |
| | 11:30 | Cricket 1st XI | v Stowe School | A |
| |
| Mon28 Jun2021 |
| | 11:00 | Tennis: Y7 Girls' Inter-House | Kings' Tennis Courts |
| | 11:00 | Cricket 1st XI | v Buckinghamshire U18 | H |
| | 14:30 | Cricket U15C | v Ashlyns School | H |
| | 14:30 | Tennis U13B | v Sandringham School | H |
| |
| Tue29 Jun2021 |
| | 09:00 | Year 8 Girls' Sports Day | Kitcheners' Field - HP4 1HE |
| | 10:40 | Cricket: Y9 Girls' Inter-House | Chesham Road Playing Fields - HP4 3AE |
| | 10:40 | Year 9 Boys' Sports Day | Kitcheners' Field - HP4 1HE |
|  | 11:45 | Cricket Sixes U13A | v Tiffin School | A |
| | 12:30 | Cricket Sixes U13A | v Langley Park School for Boys | H |
| |
| Wed30 Jun2021 |
| | 10:00 | Cricket 1st XI | v Dr Challoner's Grammar School | H |
| | 16:25 | Fives: Scholars & Rogues 2021 | Castle Courts |
| |
| Thu1 Jul2021 |
| | 10:40 | Year10 Girls' Sports Day | Kitcheners' Field - HP4 1HE |
| | 11:00 | Cricket 1st XI | v The Year 14s | H |
| |
| Fri2 Jul2021 |
| | 14:00 | Cricket 1st XI | v The Gibson XI | H |
| | 14:40 | Tennis: Y9 Boys' Inter-House | Castle Astro |
| | 14:40 | Tennis: Y9 Girls' Inter-House | Kings' Tennis Courts |
| |
| Sat3 Jul2021 |
| | 09:30 | Cricket U13A, U13B, U12A, U12B | v RGS, High Wycombe | H |
| | 11:30 | Cricket 1st XI | v The MCC | H |
| |
| Sun4 Jul2021 |
| | 14:30 | Cricket 1st XI | v The Old Berkhamstedians | H |
| |
| Mon5 Jul2021 |
| | 14:30 | Cricket U15A | v Aylesbury Grammar School | H |
