Giorgi III Dadiani (Georgian: გიორგი III დადიანი; died 1582) was Prince of Mingrelia, of the House of Dadiani, from 1572 to 1573 and again from 1578 until his death. He was a son and successor of Levan I Dadiani.
Giorgi Dadiani's hold of power in Mingrelia, one of those states that had emerged after the disintegration of the Kingdom of Georgia in the 15th century, was challenged by the neighboring ruler, Giorgi Gurieli, Prince of Guria, and his own younger brother, Mamia IV. In 1573, they succeeded in ousting Giorgi, who was only able to resume the throne through the intercession of King George II of Imereti and at the price of territorial and financial concessions in 1578. Thenceforth, Mingrelia experienced a relative peace until Giorgi's death in 1582.[1]
The historian Cyril Toumanoff, frequently cited in modern Western literature, disagreed with this traditional chronology, established by the early 18th-century scholar Prince Vakhushti, and dated Giorgi's rule to the years 1546–1574 and 1574–1582.[2]