Yankee Sullivan (James Ambrose) (c. March 10, 1811 – May 31, 1856), also known as Frank Murray and James Sullivan, was a bare-knuckle fighter and boxer. He was a prizefighting champion from 1851 to October 12, 1853. He considered himself to be the inheritor of Tom Hyer's title and lost any claim to that title after losing a fight to John Morrissey.