Mike "Twin" Sullivan was an American boxer credited with taking the Welterweight Championship of the World on April 23, 1907, when he soundly defeated William "Honey" Mellody in Los Angeles in a twenty-round bout. He vacated the title in the late fall of 1908, when he could not make weight.

William "Honey" Mellody was an American boxer who took the Welterweight Championship of the World on October 16, 1906, defeating former champion Joe Walcott in a fifteen-round points decision in Chelsea, Massachusetts.