List of world heavyweight boxing champions

At boxing's beginning, the heavyweight division had no weight limit, and historically the weight class has gone with vague or no definition. During the 19th century, many heavyweights were 170 pounds (12 st 2 lb, 77 kg) or less, though others weighed considerably more. John L. Sullivan was the first widely recognized champion under Marquess of Queensberry Rules. Known as the "Boston Strong Boy," Sullivan weighed around 200 pounds when in shape, and helped transition the sport from its bare-knuckle era. Sullivan would be defeated for the title by "Gentleman" Jim Corbett over 21 rounds on September 7, 1892, the first heavyweight titleholder solely under Queensberry rules.

In 1920, a de facto minimum weight for a heavyweight was set at 175 pounds (12 st 7 lb, 79 kg) with the standardization of a weight limit for the light heavyweight division. The addition of the cruiserweight division, which began in 1979, reset the de facto minimum, first to 190 pounds and then to 200 pounds in 2004 when boxing's major sanctioning bodies universally raised the weight limit at which they would recognize champions. In November 2020, the World Boxing Council created a new division called bridgerweight for boxers weighing between 200 and 224 pounds, and in December 2023, the World Boxing Association followed suit. However, the WBA would later withdraw recognition of the division in June 2026. As of July 2026, no other major body has recognized the division.