was a samurai commander of the Hōjō clan during Japan's Sengoku period. The adopted brother of Hōjō Ujiyasu, he commanded the defense of Kawagoe castle against siege in 1545. Twenty-six years later, Tsunanari was the commander of Fukazawa castle when it came under siege by the Takeda clan; defeated, Tsunanari withdrew to the Hōjō home castle at Odawara.