Publishers
- P. & G. Wells Ltd. 1
- P. Binstead 1
- P.A. Norstedt & Soner 1
- P.B.S. 2
- P.F. Volland Company 3
- P.I.C. 1
- P.M. (Productions) Ltd. 7
- P.M. Evans 1
- P.M. Evans And Son 2
- P.M. Heaton Publishing 9
- P.R. Gawthorn Ltd. 5
- P.S. King & Son 1
- P4 Spares 3
- Pacifica Press 2
- Paddington Press 3
- Paddington Press Ltd. 1
- Paddy Griffith Associates 1
- Pagan World Press 1
- Palace Books 2
- Paladin Press 1
- Paladwr Press 7
- Palawan Press 1
- Palgrave Macmillan 1
- Pall Mall Gazette 2
- Pan 1
- Pan Books 3
- Pan Books Ltd 1
- Pan Macmillan Children's Books 1
- Pangolin London 7
- Panico Alpinverlag 1
- Panico Press 1
- Panstwowe Muzeum Archeologiczne 1
- Pantheon Books 3
- Paolini International, Llc 1
- Papadakis 1
- Paper Tiger 2
- Parabolica Press 1
- Paragon House 1
- Paramount Publishing Enterprise 1
- Pardy & Son Ltd. 1
- Parents' Magazine Press 1
- Parish Pump Press 3
- Parker, Furnivall & Parker 4
- Parkgate Books 1
- Parragon 17
- Parragon Book Service Ltd. 1
- Parragon Books 4
- Particular Books 2
- Partizan Press 2
- Partridge 17
- Partridge Press 1
- Partridge Publications Ltd. 1
- Past & Present Publishing 1
- Past and Present Publishing Ltd. 1
- Past Times 1
- Paternoster Press 1
- Paterson Press Ltd 1
- Paterson's Publications 1
- Patrick Hardy Books 1
- Patrick Stephens 38
- Patrick Stephens Limited 55
- Patterson Smith 1
- Paul Cave 1
- Paul Elek 2
- Paul Hamlyn 5
- Paul Harris 1
- Paul Harris Publishing 3
- Paul Parey 1
- Paul Quinn 1
- Paul Watkins 1
- Pauline Page-Jones 1
- Pavilion 9
- Pavilion Books 6
- Pavilion Books Limited 2
- Pavilion Books Ltd. 16
- Pavilion Children'S Books 2
- Payne And Mackinlay 1
- Payot 2
- Peco Publications 1
- Pedigree Books Limited 72
- Peebles Press 1
- Pegasus Journal 1
- Peleus Press 1
- Pelham Books 20
- Pelham Richardson 1
- Pelican Publishing 1
- Pen & Sword 1
- Pen & Sword Aviation 10
- Pen & Sword Books 4
- Pen & Sword Maritime 5
- Pen & Sword Military 32
- Pen & Sword Transport 4
- Pen Press 1
- Pen Press Publishers Ltd. 2
- Penarth Past Oral History Group 4
- Pendragon Partnership 2
- Pendragon Publishing Limited 1
- Pendyke Publications 3
- Penguin 35
- Penguin Books 16