Isshiki Yoshisada (一色義定, died September 24, 1582), also known as Gorō, Yoshiari, Michinobu and Yoshitoshi, was a Japanese samurai leader in the Sengoku period.
[1] He was the tenth head of the Isshiki clan.
[2] He was the son of Isshiki Yoshimichi.
[2] His father committed seppuku when Yada castle was attacked by Hosokawa Fujitaka.
[1] Yoshisada escaped to Yuminoki castle.