Publishers
- C. & J. Temple Ltd. 3
- C. Arthur Pearson Ltd. 6
- C. Combridge 1
- C. Cooke 3
- C. Davis 1
- C. Hurford And P.G. Lansdown 1
- C. Hurst & Company 2
- C. Potten 1
- 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. 14
- C.A. Publications, Ltd. 6
- C.A. Reitzels 1
- C.I. Thomas 1
- C.J. Clay & Son 1
- C.J. Hatcher 1
- C.J. Perkins 1
- C.S.S.M. 2
- C.W. Beaumont 2
- C.W. Deacon & Co. 1
- C.W. Faulkner & Co. Ltd. 1
- Cab International 1
- Cadell And Co. 1
- Cadmos 1
- Cadogan Publications 1
- CADW 1
- Caerwent Historic Trust 1
- Calder Walker Associates 1
- Callway 1
- Calypso Publications 1
- Cambrian Archaeological Association 19
- Cambrian Ornithological Society 2
- Cambridge Archaeological Unit 1
- Cambridge Scholars Press Ltd. 1
- Cambridge University Press 152
- Camden Miniature Steam Services 2
- Cameron May 1
- Camps & Tours Union 1
- Canada Department Of Mines 1
- Canadian Centre For Architecture 1
- Canadian National Railways 1
- Canav Books 1
- Candlewick Press 3
- Canongate 4
- Canongate Books Ltd 1
- Canongate Publishing Limited 2
- Capall Bann Publishing 1
- Cape Times 1
- Capital Transport 7
- 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 5
- Carlton Press Inc. 1
- Carmarthan Journal 1
- Carmarthenshire Antiquarian Society 1
- Carmarthenshire County Council 1
- Carnival 2
- Carnyx Group 1
- Caroline Downey 2
- Carreg Gwalch 1
- Carwal Publications, Ltd. 1
- Casdec Ltd 1
- Casemate 3
- Cassell 41
- Cassell & Co. 16
- Cassell & Co. Ltd. 40
- Cassell & Company Limited 57
- Cassell & Company Ltd 60
- Cassell Petter & Galpin 6
- Cassell, Petter And Galpin 1
- Cassell, Petter, Galpin & Co. 4
- Castell Brothers 3
- Castell Brothers Ltd. 6
- Castle Books 2
- Castlemead Publications 3
- Cathay Books 1
- Cavendish House 1
- Caxton Editions 2
- Caxton Press 1
- Caxton Publishing Company Limited 3
- Cecil Palmer 6
- Cedco Publishing Company 1
- Cef Books 1
- Cemais Publications 1
- Center For Air Force History 1
- Center For The Study Of Language And Information 1
- Center Of Military History United States Army 1
- Central Books Limited 1
- Central Electric Railfans' Association 1