Tokugawa Mitsusada (徳川 光貞?, January 28, 1627 – September 25, 1705) was a daimyō in Japan during the Edo period (1603–1868). He was the son and heir of Tokugawa Yorinobu and a grandson of Tokugawa Ieyasu; among his sons was the eighth Tokugawa shogun Yoshimune. Norihime, daughter of his married Ichijō Kaneteru.
One of the gosanke, Mitsusada ruled the Wakayama Domain from its castle, his birthplace, in Wakayama. He reached the Junior Second court rank while alive, and was awarded the Junior First rank posthumously; he also held the ceremonial post of gon-dainagon. His grave is at Chōhō-ji in Wakayama. His another sons was Tokugawa Tsunanori (1665-1705) and Tokugawa Yoritomo (1680-1705).
- 「徳川光貞」 at the Japanese Wikipedia