The actor, who is thought to be dating Gossip Girl star Blake Lively, made the revelation during a recent appearance on BBC Two show Top Gear.
Reynolds told host Jeremy Clarkson: "I was a bit of a pariah at school. I have three older brothers, all of whom were kicked out of this very same school, so from the moment I got there, I was a marked man.
"I was kicked out for something I think you'd appreciate. I was kicked out for stealing a car. But wait - I didn't actually steal a vehicle!"
Reynolds - who was married to fellow film star Scarlett Johansson between 2008 and 2010 - claimed that he had no idea he was committing a crime when the incident took place.
He continued: "A teacher that we had, who was just 100% awful, he had this little car. It was one of those little Volkswagens. So my friends and I just played an April Fool's prank on him - we picked it up, we lifted it up and carried it down the block. There was about eight of us.
"In Canada, if you move it more than 10 feet, it's a felony. I didn't know that. One city block was 100% grand theft!"
Watch Ryan Reynolds appearing on Top Gear below: