The correctional facility is located on State Road in the city's Holmesburg neighborhood.
Officials say an inmate was found dead in his cell on Sunday.
The 59-year-old incarcerated man was found on the floor, unresponsive.
Authorities say there were signs of blunt force trauma to the head.
An arrest has been made in the case, but no further information has been released.
There is no word yet on the inmate's identity.