Ellwood City is a borough in Beaver and Lawrence counties in the U.S. state of Pennsylvania. Ellwood City is northwest of Pittsburgh and some south-southeast of New Castle. In the past, Ellwood City sustained many heavy industries such as steel-tube mills, steel-car works, building-stone and limestone quarries, foundries and machine shops, and coal-mining. In 1900, 2,243 people lived in Ellwood City, 3,902 lived there in 1910, and 12,329 lived there in 1940. The population was 7,921 at the 2010 census. Of this, 7,289 were in Lawrence County, and 632 in Beaver County.