The Oklahoma State Penitentiary, nicknamed "Big Mac", is a prison of the Oklahoma Department of Corrections located in McAlester, Oklahoma, on 1,556 acres (6.30 km2). Opened in 1908 with 50 inmates in makeshift facilities, today the prison holds more than 750 male offenders, the vast majority of which are maximum-security inmates. They also hold many death row prisoners.

The Oklahoma Department of Corrections is an agency of the state of Oklahoma. DOC is responsible for the administration of the state prison system. It has its headquarters in Oklahoma City, across the street from the headquarters of the Oklahoma Department of Public Safety. The Board of Corrections are appointees: five members are appointed by the Governor; two members are appointed by the President Pro Tempore of the Senate; and two members are appointed by the Speaker of the house of Representatives. The board is responsible for setting the policies of the Department, approving the annual budget request, and working with the Director of Corrections on material matters of the agency. T. Hastings Siegfried is the current chairman of the board. The director, who serves at the pleasure of the governor, is the chief executive of the department. The current director of Corrections is Scott Crow, who was appointed after Director Joe Allbaugh resigned his post on June 13, 2019. Crow was confirmed by the Oklahoma State Senate as director in May 2020.