[4] It is a largely residential area situated atop a crest about 3 miles (5 km) west of the Monongahela River.

[5] Mount Oliver was first settled by John Ormsby, an officer in the command of General Forbes, who was granted 249 acres of land along the banks of the Monongahela River.

In 1800 Ormsby began selling parcels of land, while retaining rent and property taxes from residents.

Later that year St. Clair Township would be divided with residents attempting to incorporate as a borough, however, the state ruled against the effort stating that the property owner quota was not sufficient to award incorporation, and Mount Oliver would become part of Lower St. Clair Township.

As such, in 1892 a petition circulated to incorporate Mount Oliver as a borough, which passed the courts on November 9, 1892.

[6] In 1927 Pittsburgh began another expansion effort, annexing the boroughs of Knoxville and Carrick, completely surrounding Mount Oliver.

Mount Oliver is completely surrounded by six Pittsburgh neighborhoods, including the South Side Slopes to the north, Arlington to the northeast, Mt.