Publishers
- Classic 4
- Classic Publications 5
- Claude Lefrancq Editeur 2
- Clearview 1
- Clement Ingleby 1
- Clifton Books 1
- Climber's Club 1
- Clwydian-Press 1
- Clymer 3
- CMG Publishing 2
- Co-operative Wholesale Society 2
- Coachbuilt Press 1
- Cobden-Sanderson 1
- Cobden-Sanderson Ltd. 1
- Coch-Y-Bonddu Books 1
- Cocorico 1
- Colin Baxter Photography Ltd. 1
- Colin Huston 1
- Colin Orchard 1
- Collection Parthenope 1
- Collectors' Books 1
- Collet's 1
- Collier Macmillan Publishers 2
- Collins 395
- Collins & Brown 1
- Collins and Harvill 1
- Collins Clear-Type Press 87
- Collins Colour Camera Books 1
- Collins Lions 1
- Collins Willow 6
- Colnaghi And Co. 1
- Colorado Railroad Museum 1
- Colour Library Books 2
- Colour Library Books Ltd. 1
- Colour Library Direct 1
- Colourbox Publishing 1
- Columbia University Press 5
- Combined Publishing 1
- Comma International Biological Systems 2
- Commission Of Conservation Canada 1
- Committee For Rescue Archaeology In Avon, Gloucestershire & Somerset 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 1
- Company Of Stationers 1
- Compassverlag 1
- Compendium 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 9
- Constable & Co. Ltd. 18
- Constable and Company Ltd. 18
- Constable Young Books 2
- Continuum 2
- Conway Maritime Press 21
- Copernicus 1
- Coppenrath 1
- Copple House Books 1
- Corcoran Gallery Of Art 1
- Cordillera Publishing Company 1
- Corgi Avon Books 1
- Corgi Yearling Books 1
- Cork University Press 2
- Cornell University Press 3
- Cornish Brothers Limited 3
- Cornmarket 1
- Cornstalk Publishing 1
- Cornstalk Publishing Company 1
- Corvina 1
- Corvina Kiado 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 & Sporting Publications 1
- Country Life 21
- Country Life Books 1
- Country Life Limited 11
- Country Life Ltd. 6
- Countryside Books 4
- Countrywide Editions Ltd 1
- County Observer Printing Works 1
- Courtauld Institute Of Art Gallery 1
- Coventry University Enterprises Ltd. 1
- Coward-McCann Inc. 1
- CP Press 2
- Cranham Local History Society 1
- Crash Media Group 2
- Crawford Art Gallery 1
- Crawley Local History Group 1
- CRC Press 12