Mt. Lebanon is a Home rule municipality in Allegheny County, Pennsylvania, United States. The population was 34,075 at the 2020 census. It is a suburb of Pittsburgh. Established in 1912 as Mount Lebanon, the township was a farming community. With the arrival of the first streetcar lines and the development of the first real estate subdivision, both in 1901, it became a streetcar suburb, offering residents the ability to commute to Downtown Pittsburgh. Furthermore, the opening of the Liberty Tunnel in 1924 allowed easy automobile access to Pittsburgh. In 1975, the renamed Mt. Lebanon adopted one of the first home rule charters in Pennsylvania.

The Liberty Tunnels are a pair of tunnels located in Pittsburgh, Pennsylvania, United States that allow motorists to travel between the South Hills of Pittsburgh and the city, beneath Mt. Washington. The tunnels were vital in the expansion of the South Hills suburbs by providing a direct route to the city, eliminating the time-consuming task of navigating around or over Mt. Washington and its inclines. Opening in 1924, the Liberty Tunnels are the longest automobile tunnel in the City of Pittsburgh.