Vandergrift is a borough in Westmoreland County in the U.S. state of Pennsylvania, approximately 30 miles (48 km) northeast of Pittsburgh. Early in the 20th century, it had the largest sheet steel mill in the world. On June 28, 1915, the Borough of Vandergrift Heights was consolidated with Vandergrift. In 1900, 2,076 people lived here; in 1910, 3,876. The 1915 consolidation almost doubled Vandergrift's population when Vandergrift Heights added approximately 3,438 new residents (1910 population). By 1940, 10,725 people lived in Vandergrift. The population was 5,455 at the 2000 census, and 5,205 in 2010.