Hisamatsu Sadakatsu (久松 定勝, 1560 – May 1, 1624) was a Japanese daimyō of the early Edo period, who served the Tokugawa clan. He was the half-brother of Tokugawa Ieyasu. His father was Hisamatsu Toshikatsu and his mother was Odai no Kata, Tokugawa Ieyasu's mother.