The Heisman Trophy winner racked up 215 yards and three touchdowns on a record-breaking 12 catches before exiting. He appeared to suffer the injury during an awkward collision with a Buckeyes defender on an incomplete pass.
Smith headed to the locker room after Ohio State cut Alabama's lead to 38-24 midway through the third quarter and was unable to return to the game.
Nick Saban's team prevailed without its star player, ultimately earning its sixth national title in the last 12 years with a 52-24 victory.
Smith returned to the sidelines with a cast on his hand to celebrate with his teammates.