Sadao Yamanaka (山中 貞雄, Yamanaka Sadao, November 7, 1909 – September 17, 1938) was a Japanese film director and screenwriter who directed 26 films between 1932 and 1938. He was a contemporary of Yasujirō Ozu, Mikio Naruse and Kenji Mizoguchi and one of the primary figures in the development of the jidaigeki, or historical film. Yamanaka died of dysentery in Manchuria after being drafted into the Imperial Japanese Army. He is the uncle of the Japanese film director Tai Kato, who wrote a book about Yamanaka, Eiga kantoku Yamanaka Sadao.