Vandergrift is a borough in Westmoreland County, Pennsylvania, United States, approximately 40 miles (64 km) east of Pittsburgh. Early in the 20th century, it had the largest sheet steel mill in the world. In July, 1915, the borough of Vandergrift Heights was consolidated with Vandergrift. In 1900, 2,076 people lived here; in 1910, 3,876. The population of Vandergrift Heights was 3,438 in 1910, therefore, the consolidation in 1915 almost doubled the population of Vandergrift. In 1940, 10,725 people lived in Vandergrift. The population was 5,455 at the 2000 census.