Publishers
- C. & J. Temple Ltd. 1
- C. Arthur Pearson Ltd. 7
- C. Combridge 1
- C. Cooke 1
- C. Davis 1
- C. Dilly 1
- C. Dilly, In The Poultry 1
- C. Hurst & Company 1
- C. Stalker 2
- C. Struik 2
- C. Tilt and Simpkin and Co. 2
- C. Titcombe 1
- C.A. Kaemmerer 1
- C.A. Kochs 1
- C.A. Publications Ltd. 8
- C.A. Publications, Ltd. 2
- C.A. Reitzels 1
- C.F. Braun & Co. 1
- C.I. Thomas 1
- C.S.S.M. 1
- C.W. Faulkner & Co. Ltd. 1
- C.W. Historicals LLC 1
- C&o Historical Society 1
- Cabi 1
- Cabi Publishing 2
- Cadell & Davies 2
- Cadogan Books 2
- CADW 1
- Caerwent Historic Trust 1
- Cage Birds 1
- Calder Walker Associates 1
- Calla Editions 1
- Callisto Books 1
- Calm Productions 1
- Cambrian Archaeological Association 14
- Cambrian Ornithological Society 1
- Cambridge Scholars Press Ltd. 1
- Cambridge University Press 99
- Camden Miniature Steam Services 1
- Cameron May 1
- Campbell Books 1
- Camps & Tours Union 1
- Canadian National Railways 1
- Candlewick Press 1
- Canongate 3
- Canongate Press 1
- Canongate Publishing Limited 1
- Canterbury University Press 1
- Cape Times 1
- Capital Transport 43
- Capitol Publishing Co. 1
- Caradon District Council 1
- Cardiff Council 1
- Cardiff University 1
- Carey Press 2
- Carl Fromme 1
- Carl Hanser 1
- Carl Winter 1
- Carlton Armitage Press 1
- Carlton Books Limited 5
- Carlton Press Inc. 1
- Carmarthan Journal 1
- Carmarthenshire County Council 2
- Carnegie Publishing Ltd. 6
- Carnival 1
- Caroline Downey 1
- Carreg Gwalch 1
- Carwal Publications, Ltd. 1
- Casemate 3
- Casemate Publishers 4
- Cassell 16
- Cassell & Co. 13
- Cassell & Co. Ltd. 20
- Cassell & Company Limited 35
- Cassell & Company Ltd 30
- Cassell Illustrated 1
- Cassell Petter & Galpin 5
- Cassell, Petter, Galpin & Co. 2
- Castell Brothers 3
- Castell Brothers Ltd. 7
- Castle Books 1
- Castlemead Publications 1
- Catalpa Press Ltd 1
- Caxton Editions 2
- Caxton Publishing Co. 1
- Caxton Publishing Company Limited 1
- CCS Books 1
- Cecil Palmer 5
- Cedar Publishing Limited 1
- Cef Books 1
- Cemais Publications 1
- Centaur Press Ltd 1
- Centennial Publishing 1
- Center Of Military History United States Army 1
- Central Books Limited 4
- Central European University Press 1
- Centre For Alternative Technology 1
- Century 2
- Century Benham 1
- Century Hutchinson Ltd. 4