Gerhart was the fifth player in Stanford history to run for 1,000 yards or more in a season, after Darrin Nelson, Brad Muster, Jon Volpe, and Vardell. He scored 15 rushing touchdowns, then the second highest single season total in Stanford history. His eight games with 100 or more rushing yards were a Stanford record. He tied a Stanford record with four rushing touchdowns against Washington State. Gerhart averaged 5.4 yards per carry and finished third in the Pac-10 in rushing. In 2009, Gerhart had 1,871 rushing yards and 28 rushing touchdowns. Gerhart led the NCAA Football Bowl Subdivision in rushing yards (1,871), rushing touchdowns (28), total touchdowns (28), and points scored (172 points). His 3,522 career rushing yards are the third most in Stanford history, behind Darrin Nelson's 4,033 yards and Stepfan Taylor's 4,300 yards. Gerhart rushed for over 100 yards in 11 of his 13 games in 2009. On September 26, 2009, he became only the sixth person in Stanford history to rush for 200 yards in a game, with 200 yards on 27 carries against Washington. On November 7, 2009, Gerhart recorded his second 200-yard game of the season, running for 223 yards against the 7th-ranked Oregon Ducks, breaking the Stanford single-game rushing record previously held by Jon Volpe. On November 28, Gerhart ran for 205 yards and three rushing touchdowns in a 45-38 win over Notre Dame. This was his third 200-yard game of the season. Gerhart again tied the school record for rushing touchdowns in a game by running for four touchdowns against Cal. Gerhart also threw one pass in 2009, completing it for an 18-yard touchdown against Notre Dame. Gerhart helped lead Stanford to an 8-5 record and its first bowl berth in eight years. He finished the season first in Division 1A in rushing yards (1,871) and rushing touchdowns (28). Gerhart was a consensus 2009 First-team All-America selection. He was named the 2009 Pac-10 Offensive Player of the Year. He was one of five finalists for the 2009 Heisman Trophy and finished in second place behind Mark Ingram by 28 points, the slimmest margin in the trophy's 74-year history. Gerhart is the winner of the 2009 Doak Walker Award as the best running back in the nation and of the Jim Brown Trophy presented to the top running back in college football by the Touchdown Club of Columbus.