Oleksandr Oleksandrovych Usyk (born 17 January 1987) is a Ukrainian professional boxer. He is a world champion in two weight classes, having held the unified WBA (Super), IBF, WBO and IBO heavyweight titles since 2021, The Ring magazine heavyweight title since 2022, and the undisputed cruiserweight title from 2018 to 2019, being the first cruiserweight champion to hold all four major world titles. He is widely regarded as one of the greatest Ukrainian boxers of all time. With his victory over Joshua, Usyk became one of only three boxers to have unified the cruiserweight world titles and become a world heavyweight champion.