Donald McAvoy (28) was arrested after police armed with a warrant searched his girlfriend’s flat in Castlemilk, Glasgow.
Prosecutor Khadija Sarwar said the keys were found within the main bedroom of the property, where McAvoy was living at the time.
Police took the keys outside and operated the electronic fob, thereby finding out that the keys opened and started a Vauxhall Corsa SX1 AC that was parked in the street nearby.
Checks revealed the car had been reported stolen by its female owner from an address in Avonbank Gardens, Denny on April 17 – the day before it was found in Glasgow.
At Falkirk Sheriff Court, McAvoy pleaded guilty to reset.
His plea of not guilty to actually stealing the car was accepted by the prosecution.
The court was told that the car was undamaged, and McAvoy had not personally driven it.
Sheriff Derek Livingston jailed McAvoy for eight months.
He has previously been jailed for knifing a man, motoring offences, and last year over a drugs-related abduction, also in Denny.
James McAvoy (39) who has also starred in films including Filth, Atonement and Trance, is thought to have never met Donald, with whom he shares a father.