Photographs of US Army Specialist Charles Graner sexually humiliating and attacking prisoners at the prison near Baghdad shocked the world last year. He was found guilty of abusing detainees by a court martial at Fort Hood, Texas, on Friday night, and sentenced on Saturday night.
Graner, 36, who was described as the leader of a band of rogue guards at the prison in late 2003, was the first soldier to be tried on charges arising from the scandal. He was also demoted to private and ordered to forfeit all pay and benefits.
When his prison sentence is completed, he will be dishonourably discharged.
Graner claimed he was following orders, but the jury found differently after the four-and-a-half day trial.
Prosecutors depicted the reservist as a sadistic soldier who took great pleasure in seeing detainees suffer.
He was accused of stacking naked prisoners in a human pyramid and later ordering them to masturbate while other soldiers took photographs. The photos showed naked detainees posed in sexual positions, hooked to electrodes and tethered to a leash.
Graner, from Uniontown, Pennsylvania, was convicted of conspiracy, assault, maltreating prisoners, dereliction of duty and committing indecent acts.
During the sentencing hearing, Graner said he initially resisted pressure to mistreat prisoners, but his army superiors made it clear he was expected to obey the commands of the intelligence agents who ran his part of Abu Ghraib.
He said: "I didn't enjoy what I did there ... A lot of it was wrong, a lot of it was criminal."
Four soldiers have pleaded guilty in the case. Two other guards are awaiting trial, along with Pfc Lynndie England, a 21-year-old clerk at Abu Ghraib who gave birth to a baby in October believed to be fathered by Graner.
Asked if he felt remorse after his sentence was handed down, Graner said: "There's a war on. Bad things happen."