- Carter Family Papers, 1667/1862, bulk 1792/18613
- Catesby Jones Account Book, 1767/18451
- Cazenove Family Papers (MS212), 1786/19701
- Channing Moore Hall Papers, 1920/1953, bulk 1930/19531
- Charles Campbell Papers, 1743/18962
- Charles H. Bell Papers, 1772/1929, bulk 1852/18751
- Christian S. Hutter miscellany, 1602/194520
- Clara L. Lawrence Papers, 1763/19391
- Clarence P. Jones, Jr. Papers, 1773/1915, bulk 1809/18211
- Clark E. Warburton papers, 1920/19795
- College Papers Collection, 1880/19991
- Colvin Papers, 1734/18392
- Connecticut Silk Industry Collection, 1786/17921
- Curtis Carroll Davis Papers, 1950/19615
- David A. Bucher Papers, 1769/19121