Gordon finished second in the voting, followed by Cooper. Mariota -- who more than doubled Gordon's point total -- received 788 first-place votes, while Gordon earned 37 and Cooper received 49.
Mariota has led the Ducks to a 12-1 record this season and a No. 2 seed in the College Football Playoff. Oregon will face Florida State in the Rose Bowl on New Year's Day.
Mariota has completed 68.3 percent of his passes this season. He has thrown for 3,783 yards, with 38 touchdowns and only two interceptions. The Ducks' offense is the nation's third-best in total yards.
The Hawaii native has also gained 669 rushing yards on 117 carries and scored 14 rushing touchdowns.
Mariota, a redshirt junior, is the seventh consecutive underclassman to win the award. No senior has hoisted the trophy since Ohio State quarterback Troy Smith in 2006.
Jameis Winston, who won the Heisman in 2013, finished sixth in the voting. TCU quarterback Trevone Boykin finished fourth, while Ohio State quarterback J.T. Barrett finished fifth.
- Dan Gartland