Publishers
- C. & J. Temple Ltd. 3
- C. Arthur Pearson Ltd. 9
- C. Combridge 1
- C. Cooke 3
- C. Davis 1
- C. Hurford And P.G. Lansdown 1
- C. Hurst & Company 2
- C. Stalker 3
- C. Struik 2
- C. Tilt and Simpkin and Co. 3
- C. Titcombe 1
- C.A. Kaemmerer 1
- C.A. Kochs 1
- C.A. Publications Ltd. 11
- C.A. Publications, Ltd. 2
- C.A. Reitzels 1
- C.H. Daniels 1
- C.I. Thomas 1
- C.J. Clay & Son 1
- C.J. Perkins 1
- C.S.S.M. 1
- C.W. Beaumont 1
- C.W. Deacon & Co. 1
- C.W. Faulkner & Co. Ltd. 1
- C&o Historical Society 1
- Cadmos 1
- Cadogan Publications 1
- CADW 2
- Caerwent Historic Trust 1
- Calder Walker Associates 1
- Cambrian Archaeological Association 18
- Cambrian Ornithological Society 1
- Cambridge Archaeological Unit 1
- Cambridge House Books 1
- Cambridge Scholars Press Ltd. 1
- Cambridge University Press 127
- Camden Miniature Steam Services 1
- Cameron May 1
- Camps & Tours Union 1
- Canada Department Of Mines 1
- Canadian National Railways 1
- Candlewick Press 2
- Canongate 4
- Canongate Publishing Limited 2
- Capall Bann Publishing 1
- Cape Times 1
- Capital Transport 10
- Caradon District Council 1
- Cardiff Council 1
- Cardiff Free Libraries 1
- Cardiff University Of Wales Press 1
- Carey Press 1
- Carington Bowles 2
- Carl Fromme 1
- Carl Hungness 1
- Carl Winter 1
- Carlton Books Limited 6
- Carlton Press Inc. 1
- Carmarthan Journal 1
- Carmarthenshire County Council 2
- Carnegie Institution Of Washington 1
- Carnyx Group 1
- Caroline Downey 2
- Carreg Gwalch 1
- Carstens Publications Inc. 1
- Carwal Publications, Ltd. 1
- Casemate 4
- Cassell 37
- Cassell & Co. 12
- Cassell & Co. Ltd. 31
- Cassell & Company Limited 57
- Cassell & Company Ltd 47
- Cassell Petter & Galpin 6
- Cassell, Petter, Galpin & Co. 3
- Castell Brothers 3
- Castell Brothers Ltd. 6
- Castle Books 1
- Castlemead Publications 2
- Caxton Editions 1
- Caxton Press 1
- Caxton Publishing Company Limited 3
- Cecil Palmer 5
- Cedco Publishing Company 1
- Cef Books 1
- Center For Air Force History 1
- Center Of Military History United States Army 1
- Central Books Limited 5
- Central Electric Railfans' Association 1
- Central European University Press 1
- Centre For Alternative Technology 1
- Century 6
- Century Benham 1
- Century Publishing 6
- Cerberus 1
- Cetre Et Fondation Le Grand-Cachot 1
- Ch. R. & Cie 1
- Chad Valley Books 2
- Chalford 3
- Challenge Publications Inc. 1
- Challenger Publications 21