The loss means Missouri (11-2) will wait until Sunday night to learn their bowl fate.
Tre Mason sliced through Missouri's offense for 304 yards and four touchdowns, while quarterback Nick Marshall also went over the century mark on the ground with 101 yards. Auburn's 677 yards of total offense is also an SEC Championship Game record.
Both sets of Tigers traded scores throughout the first half as a late touchdown pass from James Franklin to Dorial Green-Beckham cut Auburn's lead to 28-27 just before the break. Green-Beckham finished with a game-high 144 yards on six catches with a pair of touchdowns despite leaving the game briefly with a shoulder injury.
Franklin completed 21 of 37 passes 303 yards, three touchdowns, and an interception. He also rushed 15 times for 62 yards and another score. That rushing touchdown came with nine seconds to play in the third quarter and was Missouri's last of the night, cutting the deficit toe 45-42.
Mason punched in the only two scores of the fourth quarter to put the game out of reach.