Sergeant Joseph Darby (born 1979/80) is a member of the United States military police who first alerted the U.S. military command of prisoner abuse in the Abu Ghraib prison, in Abu Ghraib, Iraq.

In January 2004, Darby left two compact discs of photographs and an anonymous note on the desk of one of his superiors, triggering an investigation which led to the implication of several soldiers violating the Geneva Convention. Darby had agonised for a month beforehand, but finally decided to blow the whistle on his former friends: "It violated everything I personally believed in and all I'd been taught about the rules of war." He had known Lynndie England, one of the most well-known suspects, since basic training. He testified that he had received the photos from Charles Graner, another soldier in the photographs.

Since the disclosure, Joseph Darby and his wife, Bernadette, have been the victims of harassment in their community. They have been shunned by friends and neighbors, their property has been vandalized, and they now reside in protective military custody at an undisclosed location. Bernadette said, "We did not receive the response I thought we would. People were, they were mean, saying he was a walking dead man, he was walking around with a bull's-eye on his head. It was scary." [1]