William Harrison Clanton (1862 – October 26, 1881) was an outlaw Cowboy in Cochise County, Arizona Territory.

He was a member of a group of loosely organized outlaws who had ongoing conflicts with lawmen Wyatt, Virgil, and Morgan Earp.

His father worked at times as a day laborer, a gold miner, a farmer, and by the late 1870s, a cattleman in Arizona Territory.

In the same year prospector Ed Schieffelin discovered silver in the hills east of the San Pedro River on a plateau known as Goose Flats, less than 15 miles (24 km) from the Clanton ranch.

Earp testified in a later court hearing, "While I was waiting for the papers, Billy Clanton found out that I was in town and went and tried to take the horse out of the corral.

Hunting the murderers, Mexican Rurales led by Commandant Francisco Neri illegally crossed the border into Arizona and were ambushed.

[2] On August 13, 1881, Billy's father was killed in an ambush Guadalupe Canyon by Mexican Rurales.

On October 25, 1881, Ike, Billy, and the McLaury brothers headed to Tombstone after working to gather scattered cattle, lost during an earlier Apache raid.

He wrote in a letter during the preliminary hearing that the two brothers and Billy Clanton were preparing to come to Fort Worth, Texas to visit after selling their cattle.

On screen Billy has been portrayed by James Ferrara in Tombstone, the Town Too Tough to Die (1942), John Ireland in My Darling Clementine (1946), Dennis Hopper in Gunfight at the O.K.