Ōsawa, Osawa or Oosawa is a Japanese surname. Notable people with the surname include:Chiho Osawa , Japanese ice hockey player Eiji Osawa, Japanese chemist Itsumi Osawa, Japanese actress, writer and singer Kenji Osawa, Japanese mixed martial artist Kisaburo Osawa (1910–1991), Japanese aikidoka Masaaki Ōsawa, Japanese politician and governor of Gunma Prefecture Masayo Ōsawa (1913–1945), Japanese diver Masayuki Osawa , Japanese swimmer Reiko Ōsawa, Japanese diver Shigeki Osawa, Japanese mixed martial artist Shinichi Osawa, Japanese musician better known as Mondo Grosso Takao Osawa, Japanese actor