Publishers
- Collins Clear-Type Press 79
- Collins Colour Camera Books 2
- Collins Lions 1
- Collins Willow 6
- Colnaghi And Co. 1
- Colorado Railroad Museum 1
- Colour Library Books 2
- Colour Library Direct 1
- Colourbox Publishing 1
- Colourpoint Books 1
- Columbia University Press 4
- Combined Publishing 1
- Comma International Biological Systems 1
- Commission Of Conservation Canada 1
- Commonwealth Agricultural Bureaux 1
- Commonwealth Scientific And Industrial Research Organization 1
- Commonwealth War Graves Commission 2
- Communist Party Of Great Britain 1
- Compaid Graphics 2
- Company Of Stationers 1
- Comparahatch Ltd 1
- Compassverlag 1
- Comstock Publishing Company Inc. 1
- Comyns (Publishers) Ltd. 1
- Concept Associates Ltd. 1
- Connaissance Du Rail 4
- Connor & Butler 1
- Consejo Superior De Investigaciones Cintificas 1
- Conservation Press 1
- Consiglio Nazionale Delle Ricerche 1
- Constable 8
- Constable & Co. Ltd. 14
- Constable and Company Ltd. 15
- Constable Young Books 1
- Constable Young Books Ltd. 1
- Continuum 2
- Conway 2
- Conway Maritime Press 43
- Copernicus 1
- Coppenrath 1
- Copple House Books 1
- Cork University Press 1
- Cornell University Press 4
- Cornish Brothers Limited 3
- Cornmarket 1
- Cornstalk Publishing 1
- Cornstalk Publishing Company 1
- Coronet Books 1
- Corvina 1
- Cosmopolitan Book Corporation 1
- Cote D'Or 1
- Coterie Press Limited 4
- Council For British Archaeology 1
- Council Of Museums In Wales 1
- Country Life 22
- Country Life Books 2
- Country Life Limited 11
- Country Life Ltd. 8
- Countryside Books 3
- Countrywide Editions Ltd 1
- Courtauld Institute Of Art Gallery 1
- Coventry University Enterprises Ltd. 1
- Coward-McCann Inc. 1
- CP Press 2
- Crash Media Group 2
- Crawford Art Gallery 1
- CRC Press 13
- Crecy 3
- Crecy Books 4
- Crecy Publishing Limited 11
- Creel Press 1
- Cricket Books 1
- Croesor Junction Press 1
- Croil 1
- Croner Publications 1
- Croom Helm 7
- Croom Helm Ltd. 1
- Crosby Lockwood 1
- Crosby Lockwood and Son 3
- Crosby Lockwood And Son Ltd 2
- Cross And Jackman 1
- Crossprint 1
- Crown Publishers 1
- Crown Publishers Inc. 3
- Crowswing Books 2
- Crystal Palace Foundation 1
- Culture Et Civilisation, Bruxelles 1
- Cumberland & Westmorland Antiquarian & Archaeological Society 7
- Cupples & Leon Company 2
- Curwen Books 1
- Cushing-Malloy Inc 1
- Cwmbran Community Press Ltd. 1
- Cwmni Cymraeg Foyle 1
- Cwmni Urdd Gobaith Cymru 1
- Cwmni Y. Wasg Eglwysig Gymreig 1
- Cyhoeddedig Gan D. O'Brien Owen 1
- Cyhoeddiadau Barddas 2
- Cymric Federation Press 1
- D. Appleton & Company 2
- D. Appleton And Company 3