Travis Lamar Wilson, 25, an inmate at the Saint Clair Correctional Facility in Springville, was fatally stabbed Friday at about 11:30 a.m.
The Alabama Department of Corrections is investigating.
Wilson was treated at the prison and taken to a local hospital where he later died.
He was serving a 25-year sentence on a 2011 murder conviction in Etowah County.
The suspect in the stabbing is Cruz Caldwell, 25, and he will face a charge of first-degree murder.
He had been serving a 20-year sentence for a first-degree theft of property conviction in Coffee County.