Former Owner
- Caesareum Societatis Jesu Collegium Viennense1
- Carl Hermann Grabauer1
- Carleton Rubira Richmond1
- Carlo Archinto, 2nd Marquess of Parona, 3rd Count of Trainate1
- Carlo Bonaparte1
- Carlos José Gutiérrez de los Ríos y Rohan Chabot Fernán-Núñez1
- Catharine Wisser1
- Catherine Barton1
- Caxton Club1
- Cecil Deedes1
- Chapelle du monastère du Carmel de Nantes1
- Charles Alexander de Cosson1
- Charles Bruce, 3rd Earl of Ailesbury1
- Charles Butler1
- Charles Coffin Little1
- Charles D. Humberd1
- Charles F. Gunther1
- Charles Hope, 3rd Marquess of Linlithgow1
- Charles Hurleston1
- Charles Lenormand du Coudray1