Butch Cassidy (April 13, 1866 - 1908?), American outlaw, was born Robert Leroy Parker in Beaver, Utah, the oldest of thirteen children born to Mormon pioneers from England. He spent his childhood in Circleville, Utah, where his parents homesteaded. He was a rancher by trade, later becoming a prolific bank and train robber and the leader of The Wild Bunch gang.

His first run-in with the law came after breaking into a closed store, while working at a ranch at Hay Springs, Utah (near Milford) to take a pair of pants, leaving a note saying that he would later pay the debt. It is unconfirmed if he ever repaid the store owners. After his parents lost their homestead in a property rights dispute, Roy began to look up to a local rancher by the name of Mike Cassidy, who was known for his questionable character, and may have been involved with Roy's first cattle rustling ventures. By 1884, he took on the name "Butch Cassidy" and became a regular cattle rustler.

Cassidy usually stole cattle from larger ranchers who would try to put the smaller ranchers out of business. Many historians believe that at the beginning, his actions were well-intended and he is often referred to as the "Robin Hood of the West."

His first major recorded crime was the robbery of San Miguel Valley Bank in Telluride, in June 1889, where he and his gang left with about $20,000. He was one of the pioneers of the infamous Outlaw Trail that went from Canada through Montana and Utah to Mexico.

After spending time in prison from 1894-1896 for stealing horses, he organized a group of outlaws known as the Wild Bunch. The most famous member of this group was Harry Longabaugh, also known as The Sundance Kid. The Wild Bunch robbed over a dozen banks and trains from 1896 to 1901. In 1901 Cassidy and Sundance fled to New York City, then Argentina, resuming their careers as both ranchers and outlaws in South American countries, including Argentina and Bolivia. They were killed by soldiers in Bolivia in 1908 or 1909.

There is still some mystery, though, as it has been claimed that the bodies were not those of Butch and Sundance. Scientists exhumed the graves and performed a DNA test on the bodies with inconclusive results. Some claim to have seen the two later on in history.

There were rumors that the two survived and lived out the remainder of their lives in Uruguay or back in the United States under assumed names, but they are generally regarded to be false. The duo was portrayed in a popular 1969 movie, Butch Cassidy and the Sundance Kid, starring Paul Newman and Robert Redford.