Ryoichi Kimizuka (君塚良一 Kimizuka Ryōichi?, born 21 April 1958, in Minato, Tokyo) is a Japanese screenwriter and director for television and film.
Kimizuka first entered the Japanese television industry by working on variety shows under Kin'ichi Hagimoto. He then began writing screenplays for television dramas, including such hits as Zutto anata ga suki datta and Bayside Shakedown. He has branched out into screenplays for film, including the hit Bayside Shakedown films, as well as directing.
Kimizuka won the award for best screenplay for Bayside Shakedown: The Movie at the 1998 Yokohama Film Festival, and for Nobody to Watch Over Me at the 2008 Montreal World Film Festival.