Ryosuke Iwasa (岩佐 亮佑, Iwasa Ryōsuke, born December 26, 1989) is a Japanese professional boxer. He held the IBF super-bantamweight title from 2017 to 2018 and the interim version from 2019 to April 2021. He also challenged from the unified WBA (Super) and IBF super-bantamweight titles in April 2021.