Publishers
- The Page Company 1
- The Paternoster Press Ltd. 1
- The Paterson Engineering Co. Ltd. 1
- The Paul Mellon Foundation For British Art 1
- The Penguin Group 17
- The Penn Publishing Company 1
- The Pennsylvania State University Press 1
- The Pentland Press 4
- The Peppertree Press 1
- The Pequot Press 1
- The Perth Printing Company 1
- The Pet Book Publishing Company Limited 1
- The Physical Society 1
- The Pierpont Morgan Library 1
- The Pilgrim Press 4
- The Pilgrim Press Limited 1
- The Pilot Press Ltd. 1
- The Plane Picture Co. Publishing 2
- The Platt And Munk Co. Inc. 2
- The Porcupine's Quill 1
- The Port Of Bristol Authority 1
- The Pragmatic Bookshelf 2
- The Pre-War Austin Seven Club Ltd. 1
- The Provincial Grand Lodge Of Middlesex 1
- The R.S. Surtees Society 1
- The R.T.S. Office 2
- The Radcliffe Press 3
- The Raf Cranwell Aircraft Apprentices Association 2
- The Railway Correspondence And Travel Society 41
- The Railway Gazette 1
- The Railway Publishing Co. Ltd. 4
- The Ranelagh Press 1
- The Ray Society London 3
- The Readers Library Publishing Co. Ltd. 1
- The Rector Of Jarrow 1
- The Regensteiner Corporation 1
- The Regimental Trust 10th Princess Mary's Own Gurkha Rifles 1
- The Reilly & Britton Co. 1
- The Religious Tract Society 18
- The Richards Press 4
- The Richards Press Ltd. 21
- The Richmond Publishing Co. Ltd. 1
- The Rifle Brigade Club And Association 1
- The Rissingtons Local History Society 1
- The Rockingham Press 2
- The Rolls House Publishing Co., Ltd. 1
- The Ronald Press Company 2
- The Royal Air Force 1
- The Royal Anthroplogical Institute Of Great Britain And Ireland 2
- The Royal Commission on Ancient and Historical Monuments in Wales 2
- The Royal Commission On The Ancient And Historical Monuments Of Scotland 1
- The Royal Green Jackets Museum Trust 1
- The Royal Historical Society 4
- The Royal Institute of British Architects 2
- The Royal Society 3
- The Royal Statistical Society 1
- The Royal Swedish Commission 2
- The Rubicon Press 2
- The Saalfield Publishing Company 3
- The Sabah Society 1
- The Salmon And Trout Association 1
- The Saturn Press 1
- The Scientific Book Club 1
- The Scientific Publishing Co. 1
- The Scottish Railway Preservation Society 1
- The Scout Association 2
- The Self Publishing Association Ltd. 6
- The Sheldon Press 7
- The Shoe Lane Publishing Co. 1
- The Shoe String Press 1
- The Sidney Press 1
- The Simon Archery Foundation 1
- The Society 1
- The Society For Theatre Research 1
- The Society of Antiquaries 2
- The Society Of Antiquaries Of London 2
- The Society Of British Aerospace Companies Ltd 1
- The Society Of The Classic Guitar 2
- The Soman-Wherry Press Ltd. 1
- The Sound Approach 1
- The Sphere And Tatler 1
- The Sportsman's Press 4
- The Stanborough Press Ltd. 2
- The Stanmore Press 1
- The Starling Press 7
- The Stephenson Locomotive Society 2
- The Stockton-On-Tees Railway Centenary Committee 1
- The Stonehill Publishing Company 3
- The Studio 4
- The Studio Limited 2
- The Studio Ltd. 1
- The Sunday School Union 7
- The Sunshine Press 3
- The Surtees Society 1
- The Syndicate Publishing Co. 1
- The T.T. Special 1
- The Talyllyn Railway Preservation Society 1
- The Technical Publishing Co. Ltd. 1
- The Technical Publishing Company H. Stam-Haarlem 1
- The Temple Press 3