John Lawrence Sullivan (October 12, 1858 – February 2, 1918), also known as the Boston Strong Boy, was an American boxer recognized as the first Heavyweight Champion of gloved boxing, holding the title from February 7, 1882, to 1892. He is generally recognized as the last heavyweight champion of bare-knuckle boxing under the London Prize Ring Rules.
Sullivan had fought with gloves under the Marquess of Queensberry Rules as early as 1880 and he only fought bare knuckle three times in his entire career.