Maria Palaiologina (Serbian: Марија Палеолог / Marija Paleolog) was the Queen consort of Stefan Dečanski (1324–1331). Maria was the daughter of panhypersebastos John Palaiologos, and great-niece of Emperor Andronikos II Palaiologos (r. 1282–1328).

Her father was the governor of Thessaloniki in the early 1320s. Stefan Uroš III had earlier been married to Teodora of Bulgaria, but the marriage ended in with Theodora's death on 20 December 1322. Uroš III then married Maria in 1324. The royal couple's marriage lasted until her husband's death. Stefan Uroš III was defeated by his son Stephen Uroš IV Dušan (from the marriage with Teodora) in 1331, and shortly thereafter died in Zvečan (1332).

The relation between the father and son had been bad, the usurpation was incited by the "younger" nobility. Maria tried to assert the throne for her son Simeon Uroš, through Byzantine aid, but this was unsuccessful. Dušan the Mighty did not harm their family, Maria took monastic vows as Marta, and in 1348, Simeon became a governor of the southern provinces of the Serbian Empire. Maria died on April 7, 1355, and was buried in Skopje. A brief account of her turbulent life inscribed on her gravestone is attributed to her.^[1]