Râmnicu Sărat Prison is a former prison located at 53 Ion Mihalache Street in Râmnicu Sărat, Buzău County, Romania. It was built at the end of the 19th century, and first attested in a document of October 1901. From its establishment until 1938, it housed common criminals with sentences of up to two years. After the onset of King Carol II's royal dictatorship in 1938, the prison began to be used for political prisoners, namely the leadership of the Iron Guard, including Corneliu Zelea Codreanu. From 1955 to 1963, a significant number of prominent political prisoners were held there by the communist regime. In 2015, Alexandru Vișinescu, commander of the prison from 1956 to 1963, was convicted of crimes against humanity for his treatment of detainees, and sentenced to 20 years' imprisonment.
The building is listed as a historic monument by Romania's Ministry of Culture and Religious Affairs.