- Clark, F. Le Gros (Frederick Le Gros), 1811-18921
- Clay1
- Coccius, Ernst Adolf, 1825-18901
- Compound monocular1
- Coote, Holmes, 1817-18721
- Copland, James, 1791-18701
- Corrigan, Dominic, Sir, 1802-18801
- Critchett, George, 1817-18821
- Cruveilhier, J. (Jean), 1791-18741
- Curling, Thomas Blizard, 1811-18881
- Dalton, John Call, 1825-18891
- Darwin, Charles, 1809-18821
- Davies, Herbert, 1818-18851
- Davis, John Hall, 1811-18841
- Depaul1
- Desmarres, L. A. (Louis Auguste), 1810-18821
- Donders, F. C. (Franciscus Cornelius), 1818-18891
- Drug Packaging1
- Druitt, Robert, 1814-18831
- Du Bois-Reymond, Emil Heinrich, 1818-18961