Snedeker parlayed his share of the lead after three rounds into a victory at East Lake Golf Club, finishing three better than fellow former co-leader Justin Rose at 10-under 270.
The FedExCup prize along with his winnings from the Tour Championship -- his fourth PGA Tour title -- amounted to $11.4 million for Snedeker.
He began the week in fifth place on the Playoffs points list, meaning victory at the Tour Championship would also give him the Cup title.
Rose managed a 1-over 71 for second place.
World No. 1 Rory McIlroy carded a 4-over 74 Sunday, good for a 10th-place tie. He finished second in the FedExCup race.
Tigers Woods saw his chances for the Cup title evaporate with a 2-over 72. He shared eighth place at minus-2.