Publishers
- 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