He announced his decision on Friday via Twitter.
Jackson won the 2016 Heisman Trophy as the nation's top player, and was a finalist for the honor in 2017. He flourished as a dual-threat quarterback under coach Bobby Petrino with a rocket-strong arm and electrifying rushing skills, drawing comparisons to former Atlanta Falcons first-round pick Michael Vick. NFL.com analyst Bucky Brooks sees footwork and mechanics as areas in which Jackson needs to improve as a passer, specifically to improve his accuracy.
Jackson is considered one of the top quarterback prospects in the college game, along with UCLA's Josh Rosen, USC's Sam Darnold, Oklahoma's Baker Mayfield and Wyoming's Josh Allen. Underclassmen face a Jan. 15 deadline to apply for early draft eligibility, and many already have made their intentions known, including Darnold, Rosen and Allen.
Jackson has been a starting quarterback since his freshman year in 2015, but it was 2016 when he took college football by storm with 5,114 total yards (3,543 passing, 1,571 rushing) and 51 total touchdowns. He enjoyed similar production as a junior, but his Heisman campaign was hampered by a four-loss season for the Cardinals.