Who was the first boxer to win world championships in three different weight divisions?

Bob Fitzsimmons was the first boxer to win world championships in three different weight divisions. He completed the achievement on November 25, 1903, when he defeated George Gardiner for the world light-heavyweight title.

Fitzsimmons had already won the world middleweight championship in 1891 and the world heavyweight championship in 1897. His heavyweight victory over James J. Corbett was especially remarkable because Fitzsimmons was much lighter than Corbett and became famous for the powerful body punch that ended the fight.

By adding the light-heavyweight crown, Fitzsimmons became boxing’s first three-division world champion. His sequence—middleweight, heavyweight and light heavyweight—was unusual because he moved both upward and downward in weight. He was also the first middleweight champion to win the heavyweight title.

Later stars such as Henry Armstrong and Roberto Durán also won titles across three divisions, but they came after Fitzsimmons. Historical championship records from his era can be complicated because sanctioning bodies did not yet operate as they do today; nevertheless, Fitzsimmons is the standard answer for the first world boxing triple champion.