Tomasina Morosini (Venice, ca. 1250 – Óbuda, 1300) Queen Mother of Hungary, mother of Andrew III the Venetian King of Hungary.
She was the daughter of Michele Sbarra Morosini Patrician of Venice. In 1263 she married Stephen the Posthumous Prince of Hungary (1236-1271) in Venice, who lived in exile in Venice. His paternity was disputed by his brothers born from their father's earlier marriage and he was not recognized as presumptive heir to the Hungarian throne. Tomasina gave birth to a son who was named after his grandfather, Andrew II. She supported his son's claim to the Hungarian throne. After the death of King Ladislaus IV Prince Andrew succeeded to gain the kingdom and he was crowned King of Hungary in the name of Andrew III in 1290. He called his mother to Hungary and appointed her Princess of Slavonia and gave her the honour "queen mother". Allegedly she was poisoned in 1300, shortly before her son's death who was rumoured that he was poisoned, too on January 14, 1301. Her son was the last king of the House of Arpad.