Stephen Thomas (c. 1411 – July 10, 1461) is a member of the House of Kotromanić who reigns as the penultimate King of Bosnia from 1443 until his death.

He succeeds his kinsman, Stephen Tvrtko II, but is not recognized as king by the kingdom's leading nobleman, Stjepan Vukčić Kosača.

The two engage in a civil war that ends with the King's marriage to the insubordinate nobleman's daughter Catherine.

His reign is marked by conflicts with the Serbian Despotate and the Ottoman Empire.

Stephen Thomas is perhaps best known as the first ruler of Bosnia to engage in religious persecution.

He is succeeded by his son, Stephen Tomašević, but the Kingdom falls to the Ottomans within two years.