Hempfield Township is a township in Westmoreland County, Pennsylvania, United States. The population was 41,585 at the 2020 census, making it the largest suburb in the Pittsburgh Metropolitan Area by population. Its name is derived from Hempfield in Lancaster County, which was formed in 1729 and is named after the hemp fields in the area.

Westmoreland County is a county in the Commonwealth of Pennsylvania, United States, located in the Pittsburgh Metropolitan Statistical Area. As of the 2020 census, the population was 354,663. The county seat is Greensburg and the most populous community is Hempfield Township. It is named after Westmorland, a historic county of England. The county is part of the Southwest Pennsylvania region of the state.