In 1910, when he was 62, the Los Angeles Police Department hired Wyatt and former Los Angeles detective Arthur Moore King at $10.00 per day to carry out various tasks "outside the law" such as retrieving criminals from Mexico, which he did very capably.

Wyatt Earp was the last surviving Earp brother and the last surviving participant of the gunfight at the O.K. Corral when he died at home in a small rented bungalow in Los Angeles on January 13, 1929, at the age of 80. The Los Angeles Times reported that he had been ill with liver disease for three years. He had no children.

In 1957, grave-robbers dug up his grave in an attempt to steal the urn containing Earp's ashes. Unable to locate his cremains, they instead stole his 300 lbs (140 kg) headstone. Actor Hugh O'Brian, who was playing Earp in the 1955-61 television series The Life and Legend of Wyatt Earp, offered a reward for the stone's return. It was eventually found for sale in a flea market.