He revealed his choice Monday night in a tweet accompanied by a photo with Sun Devils head coach Todd Graham, offensive coordinator/quarterbacks coach Chip Lindsey and receivers coach Jay Norvell.
— B² (@Blake8Barnett) December 6, 2016
In September, Barnett became the fourth quarterback to transfer from Alabama since 2014.
Barnett, a former five-star product from California, started Alabama's season-opening game against USC before he was pulled in favor of Jalen Hurts.
Barnett appeared in three games and completed 11 of 19 passes for 219 yards and two touchdowns versus the Trojans.
Arizona State went 5-7 overall and 2-7 the Pac-12 this season, led by sophomore quarterback Manny Wilkins. Wilkins finished his first year as the starter with 2,329 passing yards, 12 touchdowns and nine interceptions.
Information from ESPN's Alex Scarborough was used in this report.