- Born: 1531
- Died: 1589
- Titles: Tsushima no kami
- Distinction: Rokkaku, Oda, Toyotomi, Tokugawa retainer
Kagesuke was a younger son of Yamaoka Mimasaka no kami Kageyuki. He at first was a retainer of Rokkaku Yoshikata and held Zeze castle in southern Ômi. After the death of Nobunaga he became a retainer of Toyotomi Hideyoshi. When Hideyoshi and Shibata Katsuie came to odds in 1583, Kagesuke and his elder brother Kagetaka (d.1585) secretly communicated with the latter. Hideyoshi discovered the Yamaoka's treacherous activities and deprived them of their domain. Kagesuke later found service with Tokugawa Ieyasu while Kagetaka retired and passed away a few years later.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005