| Cushendall Library | North Eastern Education and Library Board | 028 2177 1297 | Cushendall.Library@NI-Libraries.NET |
| Crumlin Library | North Eastern Education and Library Board | 028 9442 3066 | Crumlin.Library@NI-Libraries.NET |
| Crossmaglen Library | Southern Education and Library Board | 028 3086 1951 | CrossmaglenLibrary@NI-Libraries.NET |
| Creggan Library | Western Education and Library Board | 028 7126 6168 | creggan.library@ni-libraries.net |
| Cregagh Library | South Eastern Education and Library Board | 028 9040 1365 | CregaghLibrary@NI-Libraries.NET |
| Cookstown Library | Southern Education and Library Board | 028 8676 3702 | CookstownLibrary@NI-Libraries.NET |
| Comber Library | South Eastern Education and Library Board | 028 9187 2610 | ComberLibrary@NI-Libraries.NET |
| Colin Glen Library | South Eastern Education and Library Board | 028 9043 1266 | |
| Coleraine Library | North Eastern Education and Library Board | 028 7034 2561 | Coleraine.Library@NI-Libraries.NET |
| Coalisland Library | Southern Education and Library Board | 028 8774 0569 | CoalislandLibrary@NI-Libraries.NET |
| Cloughfern Library | North Eastern Education and Library Board | 028 9085 4789 | Cloughfern.Library@NI-Libraries.NET |
| Chichester Library | Belfast Education and Library Board | 028 9050 9210 | Chichester.Library@NI-Libraries.NET |
| Centre for Migration Studies at Ulster American... | Western Education and Library Board | 028 8225 6315 | CentreMigStudies@NI-Libraries.Net |
| Central Lending | Belfast Education and Library Board | 028 9050 9167 | CentralLending.BELB@NI-Libraries.NET |
| Castlewellan Library | South Eastern Education and Library Board | 028 4377 8433 | CastlewellanLibrary@NI-Libraries.NET |
| Castlederg Library | Western Education and Library Board | 028 8167 1419 | CastledergLibrary@NI-Libraries.NET |
| Carryduff Library | South Eastern Education and Library Board | 028 9081 3568 | CarryduffLibrary@NI-Libraries.NET |
| Carrickfergus Library | North Eastern Education and Library Board | 028 9336 2261 | Carrickfergus.Library@NI-Libraries.NET |
| Carnlough Library | North Eastern Education and Library Board | 028 2888 5552 | Carnlough.Library@NI-Libraries.NET |
| Cardinal Tomás Ó Fiaich Library and Archive | Southern Education and Library Board | (028/048) 37522981 | eolas@ofiaich.ie |
