Maria of Masovia (pl:Maria mazowiecka; 1408/15–14 February 1454) was a Duchess of Pomerania by marriage toBogislaw IX, Duke of Pomerania, and regent of Pomerania from 1446 to 1449.
She was the sixth daughter ofSiemowit IV, Duke of Masovia andAlexandra, a daughter ofAlgirdas,Grand Duke of Lithuania and sister of KingWładysław II Jagiełło ofPoland.
InPoznań on 24 June 1432, Maria marriedBogislaw IX, Duke of Pomerania-Wolgast-Słupsk inStargard, the first cousin anddesignated heir ofEric of Pomerania, King of Denmark, Norway and Sweden. The marriage strengthened the alliance between Bogislaw IX and King Władysław II Jagiełło against theState of the Teutonic Order, who feared losing the coastal land connecting them with theHoly Roman Empire. For this, the Order tried to prevent the wedding, and Bogislaw IX had to arrive in Poznań dressed like a pilgrim.
After her husband's death on 7 December 1446, Maria became the regent of his domains until 1449, when the male heir, ex-King Eric, returned from Gotland to rule after being deposed from his three Kingdoms 10 years earlier.
Maria died on 14 February 1454. She was buried in the Chapel of Słupsk Castle. During renovations in 1788 her sarcophagus was found and burned.