Uday Abd al-Amir Hassun, 35, also faced charges linking him to a bomb attack near a US navy base in Bahrain.
He was arrested after the blast in March near the Navy's Fifth Fleet base in the Gulf Arab state which is well known for being a regional US ally. No one was hurt in the bombing.
"The verdict was read today to jail Uday for three years and then expel him from Bahrain," his lawyer, Farid Ghazi, told Reuters on Monday.
Hassun, who left Iraq's intelligence service in 1999, had denied the charges. It was not clear if he would appeal.
Bahrain expelled a top Iraqi diplomat in April for suspected links to the blast caused by a bomb made with a cooking gas cylinder. The bomb was hidden inside a waste bin near an entrance to the base in the capital Manama.
Bahrain was the scene of frequent protests against the US-led war that toppled Iraqi President Saddam Hussein in April.