Sadao Yamanaka(山中 貞雄Yamanaka Sadao, November 7, 1909—September 17, 1938) was a Japanese film director and writer who directed 24 films during a seven-year period in the 1930s. 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 dysentary in Manchuria after being drafted into the Imperial Japanese Army. He is the uncle of the Japanese film director Tai Kato, who once penned a book about Yamanaka, Eiga kantoku Yamanaka Sadao.