The Old Melbourne Gaol is a former jail and current museum on Russell Street, in Melbourne, Victoria, Australia. It consists of a bluestone building and courtyard, and is located next to the old City Police Watch House and City Courts buildings, and opposite the Russell Street Police Headquarters. It was first constructed starting in 1839, and during its operation as a prison between 1845 and 1924, it held and executed some of Australia's most notorious criminals, including bushranger Ned Kelly and serial killer Frederick Bailey Deeming. In total, 133 people were executed by hanging. Though it was used briefly during World War II, it formally ceased operating as a prison in 1924; with parts of the jail being incorporated into the RMIT University, and the rest becoming a museum.

Melbourne is the capital and most populous city of the Australian state of Victoria, and the second-most populous city in Australia. Its name generally refers to a 9,993 km2 (3,858 sq mi) metropolitan area also known as Greater Melbourne, comprising an urban agglomeration of 31 local municipalities, although the name is also used specifically for the local municipality of City of Melbourne based around its central business area.