Publishers
- C. & J. Temple Ltd. 1
- C. Arthur Pearson Ltd. 9
- C. Combridge 1
- C. Cooke 2
- 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. 3
- C.A. Reitzels 1
- C.F. Braun & Co. 1
- C.H. Daniels 1
- C.I. Thomas 1
- C.J. Clay & Son 1
- C.S.S.M. 1
- C.W. Faulkner & Co. Ltd. 1
- C&o Historical Society 1
- Cabi 2
- Cabi Publishing 2
- Cadell & Davies 2
- Cadogan Books 2
- CADW 1
- Caerwent Historic Trust 1
- Calder Walker Associates 1
- Callisto Books 1
- Cambrian Archaeological Association 15
- Cambrian Ornithological Society 1
- Cambridge Scholars Press Ltd. 1
- Cambridge Scholars Publishing 1
- Cambridge University Press 105
- Camden Miniature Steam Services 1
- Cameron May 1
- Campbell Books 1
- Camps & Tours Union 1
- Canada's Wings 1
- Canadian National Railways 1
- Candlewick Press 1
- Canongate 3
- Canongate Books Ltd 1
- Canongate Press 1
- Canongate Publishing Limited 1
- Canterbury University Press 1
- Cape Times 1
- Capital Transport 6
- Capitol Publishing Co. 1
- Cappelen Damm 1
- Caradon District Council 1
- Carcanet New Press 1
- Cardiff Council 1
- Cardiff Free Libraries 1
- Cardiff University 1
- Cardiff University Of Wales Press 2
- Carey Press 1
- Carington Bowles 2
- Carl Fromme 1
- Carl Hanser 1
- Carl Winter 1
- Carlton Books Limited 8
- Carlton Press Inc. 1
- Carmarthan Journal 1
- Carmarthenshire County Council 1
- Carnegie Publishing Ltd. 5
- Carnival 1
- Caroline Downey 1
- Carreg Gwalch 1
- Carwal Publications, Ltd. 1
- Casemate 3
- Casemate Publishers 5
- Cassell 21
- Cassell & Co. 11
- Cassell & Co. Ltd. 24
- Cassell & Company Limited 36
- Cassell & Company Ltd 34
- Cassell Illustrated 1
- Cassell Petter & Galpin 5
- Cassell, Petter, Galpin & Co. 4
- Castell Brothers 5
- Castell Brothers Ltd. 7
- Castle Books 1
- Castlemead Publications 1
- Catalpa Press Ltd 1
- Catterick 1
- Caxton Editions 1
- Caxton Publishing Co. 1
- Caxton Publishing Company Limited 2
- 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