José Ramírez vs. Josh Taylor, billed as Undisputed, was a unification professional boxing match contested between WBC and WBO champion, José Ramírez, and WBA (Super), IBF, and The Ring champion, Josh Taylor. The bout took place on May 22, 2021, at the Virgin Hotels in Paradise, Nevada. Taylor defeated Ramirez via unanimous decision to become the undisputed light welterweight champion.

In boxing, the undisputed champion of a weight class is the boxer who simultaneously holds world titles from all recognized major organisations by each other and the International Boxing Hall of Fame. There are currently four major sanctioning bodies: WBA, WBC, IBF and WBO. There were many undisputed champions before the number of major sanctioning bodies recognizing each other increased to four in 2007, but there have only been 19 boxers to hold all four titles simultaneously.