Chōkoku-ji (長国寺) is a Buddhist temple belonging to the Sōtō sect of Japanese Zen located in the former town of Matsushiro (presently part of the city of Nagano in Nagano Prefecture, Japan. It is the mortuary temple of the Sanada clan, local warlords in the Sengoku period and daimyō of Matsushiro Domain under the Edo period Tokugawa shogunate.