Tarentum is a borough in Allegheny County, Pennsylvania, United States, 22 miles (35 km) northeast of Pittsburgh, along the Allegheny River. Formerly an industrial center, plate glass and bottles were made here. Other products were bricks, lumber, steel and iron novelties, steel billets and sheets, sack and wrapping paper, etc. The Pennsylvania Railroad had a station in Tarentum; its rail line ran through the town. In 1900, 5,472 people lived here; in 1910, 7,414 people lived here; and in 1940, 9,846 people lived in Tarentum. The population was 4,993 at the 2000 census. The borough is located within the Highlands School District.