This category is for all of the boxers who have ever won a world boxing title in any weight class. Any boxer who won one or more of the following titles is eligible for inclusion in this category: the universal world title (using Marquess of Queensberry rules), the NBA world title (1921–1962), the WBA world title (1962–present), the WBC world title (1963–present), the IBF world title (1983–present), and the WBO world title (1988–present).