Jovan Uroš Nemanjić (Serbian Cyrillic: Јован Урош Немањић) or John Ouresis Doukas Palaiologos or Joasaph of Meteora (Greek: Ιωάννης Ούρεσης Δούκας Παλαιολόγος, romanized: Iōannēs Ouresēs Doúkas Palaiologos), was the ruler of Thessaly from c. 1370 to c. 1373, retiring as a monk for the next half century thereafter.

After reigning for an uncertain number of years, John Uroš abdicated in favour of his relative, the Caesar Alexios Angelos Philanthropenos, and became a monk.

In 1384–1385 he helped his sister Maria govern Epirus after the murder of her husband Thomas II Preljubović.

John Uroš married a daughter of Radoslav Hlapen, a Serbian lord in Macedonia, and his wife, Irina (Irene) Nemanjić.

According to the manuscript Dell'Imperadori Constantinopolitani, preserved in the papers of Angelo Masarelli, the father of John's wife was "lord of Drima" ("l Signor Drimi").