Oniniwa Tsunamoto was a Japanese samurai of the late Sengoku period through early Edo period. He was the son of Oniniwa Yoshinao. His half-sister, Katakura Kita was also Katakura Kagetsuna's half sister. Together with Katakura Kagetsuna and Date Shigezane, Tsunamoto was known as one of the "Three Great Men of the Date Clan".