Yasutarō Yagi (八木保太郎 , Yagi Yasutarō) (3 February 1903 - 8 September 1987) was a Japanese screenwriter, mostly famous for his adaptations of literary works for the director Tomu Uchida in the 1930s, such as Jinsei gekijō and Kagirinaki zenshin, and for his collaborations with leftist filmmakers such as Kaneto Shindo and Tadashi Imai in the postwar. He served as president of the Japan Screenwriters Guild.