Mamia IV Dadiani (Georgian: მამია IV დადიანი; died 1590) was Prince of Mingrelia, of the House of Dadiani, from 1573 to 1578 and again from 1582 until his death. He was a younger son of Levan I Dadiani.
Mamia Dadiani's career unfolded against the background of an increasingly destructive civil unrest in the successor states of the Kingdom of Georgia in which the rulers of Mingrelia, in the former kingdom's west, played a critical role. His first accession to power was the result of a coup against his own brother, Giorgi III Dadiani, with whom he eventually reconciled in exchange of new estates. His second term, after succeeding on the death of Giorgi III Dadiani, was consumed by wars with his in-laws, the prince of Guria and king of Imereti. The latter, Levan of Imereti, fell in Mamia's hands and died in captivity. Dadiani himself died without seeing his protégé firmly established on the throne of Imereti. He was succeeded by his younger brother, Manuchar I Dadiani.