Mizuko Nanbu

 was a Japanese member of the Nanbu clan from Morioka Domain. The eldest daughter of , the 43rd daimyō of Morioka Domain, and wife of , the 44th head, she served as the Director of the Girl Scouts of Japan from 1955.
She also served as an advisor to the Iwate "Kenjinkai" in Tokyo with her husband Toshihide.