Ryoichi Hattori (?? ??, Hattori Ryoichi, October 1, 1907 Osaka – January 30, 1993) was a Japanese pop and jazz composer.
Katsuhisa Hattori is his son.
He had a great influence on Japanese pop and was awarded the People's Honor Award.
Japanese jazz was downtrodden during World War II, but he created a jazz boom after the war.
He composed many songs for various artists such as Noriko Awaya, Shizuko Kasagi, Ichimaru and Ichiro Fujiyama.
He also composed Li Xianglan's song "Suzhou Nocturne", which created an embarrassing controversy over half a century though it was not a militaristic song.