Clarence Whistler (February 24, 1856 - November 6, 1885) was a professional athlete and champion Greco-Roman wrestler of the 1880s. As the main rival to William Muldoon in wrestling of the early 1880s, he was best remembered for his unusual strength, indifference to pain and early death. He wrestled three famous bouts with Muldoon, totaling over 14 hours.