Medium Security Institution
| Location | 7600 Hall St, St Louis, Missouri |
|---|---|
| Coordinates | 38°42′22″N 90°13′19″W / 38.706°N 90.222°W |
| Status | Defunct |
| Security class | Medium |
| Capacity | 1,138 |
| Population | 185 (as of August 7, 2021) |
| Opened | 1966 |
| Closed | 2021 |
| Managed by | Public Safety Department - City of St. Louis |
| Director | N/A |
The Medium Security Institution, commonly referred to as The Workhouse, was a medium-security penitentiary located in St. Louis, Missouri, and was owned and operated by the municipal department of Public Safety and Corrections. Opened in 1966, the prison was long controversial for its poorly ventilated rooms, debt bondage, inadequate food, forced labor, and other human rights violations. On June 17, 2021, the jail was closed and its inmates moved to the City Justice Center. In 2025, after long debate, the building was demolished.