Wyatt Berry Stapp Earp (March 19, 1848 – January 13, 1929) was an American lawman and gambler in the American West, including Dodge City, Deadwood, and Tombstone. Earp was involved in the famous gunfight at the O.K. Corral, during which lawmen killed three outlaw Cochise County Cowboys. While Wyatt is often depicted as the key figure in the shootout, his brother Virgil was both Deputy U.S. Marshal and Tombstone City Marshal that day and had considerably more experience in law enforcement as a sheriff, constable, and marshal than did Wyatt. Virgil made the decision to enforce a city ordinance prohibiting carrying weapons in town and to disarm the Cowboys. Wyatt was only a temporary assistant marshal to his brother.

In 1874 Earp arrived in the boomtown of Wichita, Kansas, where his reputed wife opened a brothel. Wyatt was arrested more than once for his presence in a brothel where he may have been a pimp. He was later appointed to the Wichita police force and developed a solid reputation as a lawman but was fined and "not rehired as a police officer" after getting into a physical altercation with a political opponent of his boss. Earp immediately left Wichita, following his brother James to Dodge City, Kansas, where his brother's wife Bessie and Earp's common law wife Sally operated a brothel. He later became an assistant city marshal. In late 1878 he went to Texas to track down an outlaw and met John "Doc" Holliday, whom Earp credited with saving his life.

Throughout his life, Earp moved between boom towns. He left Dodge in 1879 and moved with his brothers James and Virgil to Tombstone, where a silver boom was underway. The Earps clashed with a group of outlaws known as the "Cowboys". Wyatt, Virgil, and younger brother Morgan held various law-enforcement positions that put them in conflict with Tom McLaury, Frank McLaury, Ike Clanton, and Billy Clanton, who threatened to kill the Earps on several occasions. The conflict escalated, culminating in the shootout at the O.K. Corral on October 26, 1881, where the Earps and Doc Holliday killed three Cowboys. During the next five months, Virgil was ambushed and maimed, and Morgan was murdered. Wyatt, Warren Earp, Doc Holliday, and others formed a federal posse that killed three more Cowboys whom they thought responsible. Wyatt was never wounded in any of the gunfights, unlike his brothers Virgil and Morgan or Doc Holliday, which added to his mystique after his death.

After leaving Tombstone, Earp went to San Francisco where he reunited with Josephine Marcus, and they lived as husband and wife. They joined a gold rush to Eagle City, Idaho, where they owned mining interests and a saloon. Back in San Francisco, Wyatt raced horses, but his reputation suffered irreparably when he refereed the Fitzsimmons vs. Sharkey boxing match and called a foul, which led many to believe he fixed the fight. Earp and Marcus joined the Nome Gold Rush in 1899. He and Charlie Hoxie paid US$1,500 (equivalent to $49,000 in 2021) for a liquor license to open the Dexter, a two-story saloon, and made an estimated $80,000 (equivalent to $2,606,000 in 2021). But Josephine had a notorious gambling habit and the money didn't last. Around 1911, Earp began working several mining claims in Vidal, California, retiring in the hot summers with Josephine to one of several small, modest cottages they rented in Los Angeles. He made friends among early Western actors in Hollywood and tried to get his story told, but he was portrayed during his lifetime only very briefly in one film, Wild Bill Hickok (1923).

Earp died on January 13, 1929. Known as a Western lawman, gunfighter, and boxing referee, he had earned notoriety for his handling of the Fitzsimmons–Sharkey fight and his role in the O.K. Corral gunfight. This changed only after his death when the extremely flattering biography Wyatt Earp: Frontier Marshal by Stuart N. Lake was published in 1931, becoming a bestseller and creating his reputation as a fearless lawman. Since then, Earp's fame and notoriety have been increased by films, television shows, biographies, and works of fiction. Long after his death, he has many devoted detractors and admirers.