下野國
was a Japanese "daimyō" who ruled the Aizu domain. He was the son of Gamō Ujisato. A Catholic, Hideyuki was moved to Utsunomiya (180,000 "koku") in Shimotsuke Province after his father died in 1595. In 1600, he was given Aizu, worth 600,000 "koku". This had been part of his father's fief. His wife was third daughter of Tokugawa Ieyasu, Furihime.