- C. Harrison Mann, Jr. map collection, 1579/19612
- Cambridge University Charters, 1575/16692
- Cantabrigiensis Comitatus Cambridgeshire (Reproduction), 16481
- Cantium Vernacule Kent (Reproduction), 16481
- Cestria Comitatus Palatinus (Reproduction), 16481
- Channing Moore Hall Papers, 1920/1953, bulk 1930/19531
- Chester McNerney Collection, 1290/19502
- Christian S. Hutter miscellany, 1602/19456
- Collection of French Language Manuscripts, 1633/1942, bulk 1633/19421
- Collection of Spanish Language Manuscripts, 1551/18581
- Comitatus Nottinghamiensis (Reproduction), 16481
- Cornubia Cornwallia (Reproduction), 16481
- Cumbria Vulgo Cumberland (Reproduction), 16481