"There's some unfinished business to take care of with my brothers," Hill said in his announcement on social media.
Hill was a playmaker for the Bulldogs, rushing 242 times for 10 touchdowns and 1,350 yards -- good for third in the SEC. He also caught 17 passes for 174 yards and a touchdown.
He had announced Dec. 12 that he planned to enter the NFL draft. But Wednesday, he posted an announcement on Twitter, saying, "I'm thankful and blessed for these last three years, but I'm also excited for the opportunity to play my final season in the coach Leach era of Mississippi State football and continue the pursuit of my degree."
On Jan. 9, Mississippi State named Leach, the colorful former Washington State coach, to replace Joe Moorhead, who was fired Jan. 3 after going 14-12 in two seasons.
Leach has taken his teams to 16 bowls and his "Air Raid" passing attack has led FBS 10 times.
Last week, Leach said Hill would get a chance to hone his game if he came back for the 2020 season.
"The thing that I think would be appealing to any running back in our offense, we ask them to do what they have to do on Sunday," Leach told the Clarion-Ledger. "They have to rush the football, they have to pass protect, they have to run block, they have to catch the football."