Joshua Casteel (27 December 1979 – 25 August 2012) was a United States Army soldier, conscientious objector, playwright, and divinity student.

[1][2] When he was seven years old Casteel attended Iowa caucus events and by high school he was president of a local chapter of the Young Republicans.

[1][4] He enlisted in the active duty Army in May 2002, the same month he graduated from the University of Iowa, and began his training as an interrogator at Fort Huachuca in September of that year.

[2][8] In 2019, a Smithsonian article entitled "The Priest of Abu Ghraib" profiled Casteel and discussed his theological struggles while interrogating Muslim prisoners in Iraq.

[4] Joining the army is not a sacrament, it's a pagan allegiance.On June 19, 2006, Casteel shared the bill with Vaclav Havel, Harold Pinter, Tom Stoppard, and Jeremy Irons at the Royal Court Theatre for his solo performance of his play, The Interrogation Room.

[9][11] Also in 2008, excerpts of Casteel's emails from Iraq were published in Harper's Magazine and in book form as Letters from Abu Ghraib with a foreword by Christopher Merrill.

[1][12][13] In the fall of 2008, the Virginia Quarterly Review published "Combat Multipliers", a reflection by Casteel on a mural adorning the Army chapel at Abu Ghraib and an attack by insurgents on the compound while he was assigned there.

[2][16] An oncologist told Casteel's mother that "Joshua died of lung cancer without having any of the conventional risk factors such as smoking, asbestos exposure or radiation ...