- Testamentum (Francis, of Assisi, Saint)1
- The Great Western Schism (1378-1417)1
- Theodore, Bishop of Mopsuestia, approximately 350-428 or 4291
- Therapeutics1
- Thomas, Apostle, Saint, active 1st century1
- Thomas, Aquinas, Saint, 1225?-12741
- Thyestes, King of Olympia and Mycenae (Mythological character)1
- Tiberius, Emperor of Rome, 42 B.C.-37 A.D.1
- Trinity1
- Tristan (Legendary character)1
- Trojan War1
- Tudor, House of1
- Turkey--Istanbul1
- Turkey--Troy (Extinct city)1
- Ukraine1
- Ulric, Saint, Bishop of Augsburg, 890-9731
- Universities and colleges1
- Universität Wien. Kollegium St. Nikolaus1
- Urmawī, Sirāj al-Dīn Maḥmūd ibn Abī Bakr, 1198-1283. Maṭāliʻ al-anwār1
- Velasco family1