Gerhart thanked coach Jim Harbaugh, former running backs coach Willie Taggart and his offensive linemen for helping his success this season. He could have stayed for a fifth season because he played just one game in 2007 because of injuries, but opted for the NFL instead.
After winning just one game his freshman season under coach Walt Harris, Gerhart helped lead a turnaround for the Cardinal that was capped this season by the school's first bowl bid since 2001.
"We've been through a lot of adversity during my time here, but I'm extremely proud to have been part of the class that brought Stanford football back to national prominence," Gerhart said.
Stanford (8-5) lost the Sun Bowl to Oklahoma, but had many breakthroughs this season led by Gerhart. The Cardinal made it into The Associated Press rankings for the first time in eight years and were in contention for the Pac-10 title until late in the season.
Gerhart was at his best during a memorable November run for Stanford. He ran for 223 yards and three TDs in a 51-42 victory over then-No. 7 Oregon, followed by 178 yards rushing and three scores in a 55-21 victory at then-No. 11 Southern California.
Gerhart ran for 136 yards and four touchdowns in a 34-28 loss to California before capping the month with 205 yards rushing, three touchdowns and a TD pass in a 45-38 win against Notre Dame.
Gerhart ran for a school-record 1,871 yards and a nation-leading 28 touchdowns this past season. He won the Doak Walker Award as the nation's top running back and finished second in the Heisman Trophy voting to Alabama's Mark Ingram in the closest vote ever.
"Toby will be a great pro, and we are all excited for his opportunity at the next level," Harbaugh said. "We are excited and enthused to watch Toby and all of our seniors go on to become leaders in their chosen fields."
With Gerhart in the NFL, Stanford's offense next season will revolve more around quarterback Andrew Luck. Stepfan Taylor, who ran for 303 yards as a freshman, will step in at tailback along with Jeremy Stewart and Tyler Gaffney.