Sources told ESPN that Hill has indicated to the coaching staff that he will opt out and begin preparing for the NFL draft.
AL.com was first to report the development on Tuesday.
"I haven't talked to Kylin," coach Mike Leach said Wednesday. "What I've heard is he's opting out and preparing for the NFL."
"They're into another chapter in their life, and so are we," Leach said.
Hill came back for his senior season after initially declaring for the previous draft.
He missed Mississippi State's last game on Oct. 17 for undisclosed reasons.
Hill had run for 58 yards on 15 carries in three games this season. He caught 23 passes for 237 yards.
The Columbus, Mississippi, native made national headlines this offseason when he threatened to boycott the season if the state did not change its flag, which featured the symbol of the Confederacy.
The state ultimately voted to take down the old flag and create a new one.