Lifespan: Kyōtoku 3 (1450) to 6/21 of Bunmei 17 (1485)
Other Names: Suketaka
Father: Itō Suketaka
Siblings: Sister (wife of Tsuchimochi Takatsuna), Sukekuni, Kyōdō-fujin (wife of Shimazu Tatsuhisa), Sukemura, Sukehide, 祐円, 祐兄, sister (wife of Sadowara Buzen-no-kami), 祐岑, sister (wife of Migimatsu Kunai-shōyū), Gensei, 玉阿, 大賢, brother (monk), Ikkai (high priest), brother (monk), 祐具, 祐運, sister (wife of Nagakura Wakasa-no-kami), sister (wife of Itō Mimasaka-no-kami), sister (wife of Sasautsu Ōmi-no-kami), sister (wife of Kiyotake Saburō), sister (wife of Kamibeppu Owari-no-kami), sister (wife of Kiyotake Hyōbu-shōyū), sister (wife of Itō Kawachi-no-kami)
Wife: [Formal] Daughter of Tsuchimochi Yajirō Koretsuna
Children: Tadasuke, Sukemune, Suketake, daughter (wife of Sagara Nagatsune)
Itō Sukekuni served as a bushō in the late Muromachi period. Sukekuni served as the seventh head of the Itō clan of Hyūga Province.
Sukekuni followed his father, Itō Suketaka, engaging in many battles. In 1480, he ruled the territory of Sadowara given by his liege. That same year, he fought against the Shimazu clan at Oryūzako, routing the army of Hidaka Suō-no-suke.
In 1484, his father intervened in an internal conflict in the Shimazu clan.
Sukekuni opposed the policies of Shimazu Tadamasa, the eleventh head of the Shimazu, requesting support from his father and the Ōtomo clan of Bungo Province to attack Obi Castle defended by Niiro Tadatsugu. In an effort to aid a revolt by Shimazu Hisayasu against Tadamasa, Sukekuni and his father attacked Obi Castle. In 1485, however, Suketaka died at Kiyotake Castle while on deployment and Sukekuni inherited the headship of the clan. That same year, Sukekuni, together with his younger brother, Itō Sukemura, launched another assault against Obi Castle. The troops whom he led in this army came from Tonokōri, Sadowara, Miyazaki, Kinowaki, Yatsushiro, Sannō, Hokita, Tomita, Takarabe, Takajō, Shiomi, Hichiya, Kadokawa, Yamakage, Tashiro, Mikado, 入下, Unama, MIzushidani, Shiromi, Ogawa, Ohae, Nakanomata, Udo, Soi, and Kaeda.
Sukekuni and Sukemura traversed the Kunimi Pass, quickly surrounded Obi Castle, and killed Shimazu Hōki-no-kami from the reinforcements sent by the Shimazu. Unable to topple the castle, the Itō clashed against forces led by Shimazu Tadamasa at Kusuhara. Sukekuni was killed at the height of this battle. He was thirty-five years old.