| School | HMC Division | Membership | Location | Age Range |
| Oban High School | Scottish (UK) | Associate (UK) | Oban, United Kingdom | |
| Oswestry School | West (UK) | British Isles | Oswestry, United Kingdom | 4 - 18 |
| Oundle School | East (UK) | British Isles | Oundle, United Kingdom | 11 - 18 |
| Pangbourne College | South Central (UK) | British Isles | Reading, United Kingdom | 11 - 18 |
| Peponi School | International | International | Ruiru, Kenya | 13 - 18 |
| Peterhouse | International | International | Marondera, Zimbabwe | 4 - 18 |
| Pipers Corner School | London (UK) | British Isles | High Wycombe, United Kingdom | 4 - 18 |
| Plymouth College | South West and Wales (UK) | British Isles | Plymouth, United Kingdom | 3 - 18 |
| Pocklington School | North East (UK) | British Isles | Pocklington, United Kingdom | 2 - 18 |
| Princethorpe College | West (UK) | British Isles | Rugby, United Kingdom | 11 - 18 |
| Prior Park College | South West and Wales (UK) | British Isles | Bath, United Kingdom | 11 - 18 |
| Putney High School | London (UK) | British Isles | Putney, London, United Kingdom | 4 - 18 |
| Pymble Ladies’ College | International | International | Pymble, Australia | |
| Queen Anne’s School | South Central (UK) | British Isles | Caversham, United Kingdom | 11 - 18 |
| Queen Elizabeth Grammar School | North East (UK) | British Isles | Wakefield, United Kingdom | 7 - 18 |
| Queen Elizabeth’s Hospital | South West and Wales (UK) | British Isles | Bristol, United Kingdom | 7 - 18 |
| Queen Elizabeth’s School, Barnet | London (UK) | Associate (UK) | Barnet, United Kingdom | |
| Queen’s College | South West and Wales (UK) | British Isles | Taunton, United Kingdom | 0 - 18 |
| Queenswood School | London (UK) | British Isles | Hatfield, United Kingdom | 11 - 18 |
| Radley College | South Central (UK) | British Isles | Oxon, United Kingdom | 13 - 18 |
| Ratcliffe College | East (UK) | British Isles | Leicester, United Kingdom | 3 - 18 |
| Reading Blue Coat School | South Central (UK) | British Isles | Reading, United Kingdom | 11 - 18 |
| Redmaids’ High School | South West and Wales (UK) | British Isles | Bristol, United Kingdom | 7 - 18 |
| Reed’s School | London (UK) | British Isles | Cobham. Surrey, United Kingdom | 11 - 18 |
| Reigate Grammar School | South East (UK) | British Isles | Reigate, United Kingdom | 11 - 18 |
| Rendcomb College | West (UK) | British Isles | Cirencester, United Kingdom | 3 - 18 |
| Repton School | West (UK) | British Isles | Repton, United Kingdom | 13 - 18 |
| RGS Surrey Hills | South East (UK) | British Isles | Dorking, United Kingdom | 11 - 18 |
| RGS Worcester | West (UK) | British Isles | Worcester, United Kingdom | 11 - 18 |
| Robert Gordon’s College | Scottish (UK) | British Isles | Aberdeen, United Kingdom | 3 - 18 |
| Rockport School | Irish | British Isles | Holywood, United Kingdom | 2 - 18 |
| Roedean School | South East (UK) | British Isles | Brighton, United Kingdom | 11 - 18 |
| Rossall School | North West (UK) | British Isles | Fleetwood, United Kingdom | 2 - 18 |
| Rougemont School | South West and Wales (UK) | British Isles | Newport, United Kingdom | 3 - 18 |
| Royal Grammar School (Guildford) | South Central (UK) | British Isles | Guildford, United Kingdom | 11 - 18 |
| Royal Grammar School High Wycombe | South Central (UK) | Associate (UK) | High Wycombe, United Kingdom |
Oban High School
Age range
Location
Oban High School, Soroba Road, Oban, UK
Head’s name
Peter Bain
Oswestry School
Age range
4 - 18
Location
Upper Brook Street, Oswestry, Shropshire, SY11 2TL, United Kingdom
Head’s name
Peter Middleton
Oundle School
Age range
11 - 18
Location
Great Hall, Oundle, Peterborough, PE8 4GH, United Kingdom
Head’s name
Sarah Kerr-Dineen
Pangbourne College
Age range
11 - 18
Location
Pangbourne, Reading, Berkshire, RG8 8LA, United Kingdom
Head’s name
Oliver Knight
Peponi School
Age range
13 - 18
Location
Off Thika Rd, Ruiru, Kenya
Head’s name
Mark Durston
Peterhouse
Age range
4 - 18
Location
P. Bag 3741, Marondera --263, Zimbabwe
Head’s name
Jonathan Trafford
Pipers Corner School
Age range
4 - 18
Location
Pipers Lane, Great Kingshill, High Wycombe, HP15 6LP
Head’s name
Helen Ness-Gifford
Plymouth College
Age range
3 - 18
Location
Ford Park, Plymouth, Devon, PL4 6RN, United Kingdom
Head’s name
Peter Watts
Pocklington School
Age range
2 - 18
Location
West Green, Pocklington, East Yorkshire, YO42 2NJ, United Kingdom
Head’s name
Toby Seth
Princethorpe College
Age range
11 - 18
Location
Princethorpe, Rugby, Warwickshire, CV23 9PX, United Kingdom
Head’s name
Ed Hester
Prior Park College
Age range
11 - 18
Location
Ralph Allen Drive, Bath, Banes, BA2 5AH, United Kingdom
Head’s name
Ben Horan
Putney High School
Age range
4 - 18
Location
35 Putney Hill, London, SW15 6BH, United Kingdom
Head’s name
Jo Sharrock
Pymble Ladies’ College
Age range
Location
Avon Road Pymble NSW Australia
Head’s name
Kate Hadwen
Queen Anne’s School
Age range
11 - 18
Location
6 Henley Road, Caversham, Reading, RG4 6DX, United Kingdom
Head’s name
Elaine Purves
Queen Elizabeth Grammar School
Age range
7 - 18
Location
154 Northgate, Wakefield, WF1 3QX, United Kingdom
Head’s name
Richard Brookes
Queen Elizabeth’s Hospital
Age range
7 - 18
Location
Berkeley Place, Clifton, Bristol, BS8 1JX, United Kingdom
Head’s name
Rupert Heathcote
Queen Elizabeth’s School, Barnet
Age range
Location
Queen's Road, Barnet, Hertfordshire, EN5 4DQ
Head’s name
Neil Enright
Queen’s College
Age range
0 - 18
Location
Trull Road, Taunton, TA1 4QS, United Kingdom
Head’s name
Julian Noad
Queenswood School
Age range
11 - 18
Location
Shepherd's Way, Hatfield, Hertfordshire, AL9 6NS, United Kingdom
Head’s name
Jo Cameron
Radley College
Age range
13 - 18
Location
Abingdon, Oxon, Oxfordshire, OX14 2HR, United Kingdom
Head’s name
John Moule
Ratcliffe College
Age range
3 - 18
Location
Fosse Way, Leicester, Leicestershire, LE7 4SG, United Kingdom
Head’s name
Jonathan Reddin
Reading Blue Coat School
Age range
11 - 18
Location
Sonning Lane, Sonning, Reading, Berkshire, RG4 6SU, United Kingdom
Head’s name
Peter Thomas
Redmaids’ High School
Age range
7 - 18
Location
Westbury-on-Trym, Bristol, BS9 3AQ, United Kingdom
Head’s name
Paul Dwyer
Reed’s School
Age range
11 - 18
Location
Sandy Lane, Cobham KT11 2ES, United Kingdom
Head’s name
Mark Hoskins
Reigate Grammar School
Age range
11 - 18
Location
Reigate Road, Reigate, Surrey, RH2 0QS, United Kingdom
Head’s name
Shaun Fenton
Rendcomb College
Age range
3 - 18
Location
Rendcomb, Cirencester, Gloucestershire, GL7 7HA, United Kingdom
Head’s name
Robert Jones
Repton School
Age range
13 - 18
Location
The Hall, Repton, Derbyshire, DE65 6FH, United Kingdom
Head’s name
Mark Semmence
RGS Surrey Hills
Age range
11 - 18
Location
Old London Road, Dorking, Surrey, RH5 6EE, United Kingdom
Head’s name
Hayley Robinson
RGS Worcester
Age range
11 - 18
Location
Upper Tything, Worcester, Worcestershire, WR1 1HP, United Kingdom
Head’s name
John Pitt
Robert Gordon’s College
Age range
3 - 18
Location
Schoolhill, Aberdeen, Scotland, AB10 1FE, United Kingdom
Head’s name
Robin Macpherson
Rockport School
Age range
2 - 18
Location
15 Rockport Road, Craigavad, Holywood, BT18 0DD
Head’s name
George Vance
Roedean School
Age range
11 - 18
Location
Roedean Way, Brighton, BN2 5RQ, United Kingdom
Head’s name
Niamh Green
Rossall School
Age range
2 - 18
Location
Broadway, Fleetwood, Lancashire, FY7 8JW, United Kingdom
Head’s name
Jeremy Quartermain
Rougemont School
Age range
3 - 18
Location
Malpas Road, Newport, NP20 6QB, United Kingdom
Head’s name
Lisa Pritchard
Royal Grammar School (Guildford)
Age range
11 - 18
Location
Royal Grammar School, Guildford, Surrey, GU1 3BB, United Kingdom
Head’s name
Jonathan Cox
Royal Grammar School High Wycombe
Age range
Location
Amersham Road, High Wycombe, Buckinghamshire, HP13 6QT
Head’s name
Philip Wayne