Stefan Uroš IV Dušan (Serbian Cyrillic: Стефан Урош IV Душан) (c. 1308 – 20 December 1355), called "the Mighty" (Serbian: Силни, Silni), was the King of Serbia (from 8th September 1331) and Emperor (Tsar) of the Serbs and Greeks (from 16th April 1346). Under his rule Serbia reached its territorial, political and economic peak.

He enacted the constitution of Serbian Empire in Dušan's Code.

Dušan was also noted as a man of gigantic proportions, and according to Papal ambassadors he was the tallest man of his time, estimated at close to seven feet tall. His death in 1355 was a "catastrophe" for the Eastern Orthodox Church in the Balkans, since he ruled in the only Balkan state which was capable to stop the advance of the Ottoman Empire