- Spinola family1
- Spiritual life--Catholic Church1
- Stefano, Caterina di1
- Stefano, Niccolò di1
- Stefano, Simone di1
- Strozzi, Nanni, 1376-14271
- Sundials1
- Surveying1
- Tactics1
- Tasʹhīl al-fawāʼid wa-takmīl al-maqāṣid (Ibn Mālik, Muḥammad ibn ʻAbd Allāh)1
- Theology, Doctrinal1
- Theology--Manuscripts1
- Thilla, Berto1
- Third Order Regular of St. Francis1
- Third Order Secular of St. Francis1
- Third orders1
- Thirteenth century1
- Thyestes, King of Olympia and Mycenae (Mythological character)1
- Tiberius, Emperor of Rome, 42 B.C.-37 A.D.1
- To 14211