Barkley's decision comes a day after he rushed for 137 yards and two touchdowns in the No. 9 Nittany Lions' 35-28 win over No. 11 Washington on Saturday at the PlayStation Fiesta Bowl, raising his season rushing totals to 1,271 yards and 18 touchdowns.
In a statement released by the school, Barkley said he hopes he "left a lasting impression" in Happy Valley, and he certainly did that. The versatile back ran for 3,843 career rushing yards, finishing just 90 yards shy of the program's all-time mark.
"As good of a player as he is, he is an even better person and I look forward to watching him achieve his dream of playing in the NFL," Penn State coach James Franklin said in a statement.
ESPN's Dan Murphy contributed to this report.