- Cristofano, Filippo di1
- Cristoforo, Pietro di1
- Croatia--Šibenik1
- Cryptography1
- Customary law1
- Czech Republic--Brno1
- Darius I, King of Persia, 548 B.C.-485 B.C.1
- Dati, Agostino, 1420-14781
- Dati, Jacopo1
- Dati, Niccolò, 1458-1500 or 15011
- Davanzati, Niccolò1
- David, King of Israel1
- Dawwānī, Muḥammad ibn Asʻad, 1426 or 1427-1512 or 15131
- Dawwānī, Muḥammad ibn Asʻad, 1426 or 1427-1512 or 1513. Risālah qadīmah li-ithbāt al-wājib1
- De caelo (Aristotle)1
- De finibus bonorum et malorum (Cicero, Marcus Tullius)1
- De generatione et corruptione (Aristotle)1
- De mundo (Aristotle)1
- De pomo (Aristotle)1
- Dead--Religious aspects--Islam1