Ryuzo Kikushima (菊島 隆三, Kikushima Ryūzō, 1 March 1914 – 18 March 1989) was a Japanese writer and film producer who is best known for co-writing the screenplays for several Akira Kurosawa films, including Throne of Blood, The Hidden Fortress, Yojimbo and High and Low. He also produced several of Kurosawa's early 1960s films. In addition to his work with Kurosawa, screenplays he wrote or co-wrote include Tora! Tora! Tora!, Hiroshi Inagaki's Arashi and The Birth of Japan, and Mikio Naruse's When a Woman Ascends the Stairs, on which he also served as producer.