Mount Oliver is a borough in Allegheny County, Pennsylvania, United States. It is a largely residential area situated atop a crest about west of the Monongahela River. The borough is surrounded entirely by the city of Pittsburgh.
It is named for Oliver Ormsby, son of John Ormsby, who held the original land grant for the area from George III. Mount Oliver has experienced some tough times of late which are associated with the slippage of the steel-making capacity of the Pittsburgh region. The population was 3,403 at the 2010 census.