- Birth: 1583
- Death: 1612
- Title: Bitchû no kami
- Sons: Tadasato (1603-1627), Tadamoto (1605-1634)
- Japanese: 蒲生 秀行 (Gamou Hideyuki)
Hideyuki was the son of Gamô Ujisato and inherited his father's fief at Aizu (420,000 koku) in 1596. He was transferred to Utsunomiya in Shimotsuke province in 1598, thereby suffering a loss of income to 180,000-koku. It is not clear why Hideyoshi moved the young Hideyuki, but he may have hoped that by moving the experienced Uesugi Kagekatsu to Aizu in Hideyuki's place, Tokugawa Ieyasu's regional supremecy would be offset. Hideyuki supported Tokugawa during the Sekigahara Campaign, and while he saw little fighting nonetheless received Aizu (600,000 koku) as a reward. When Hideyuki's 2nd son Tadamoto died, the Gamô line came to an end.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005