Westmoreland County may refer to:
- In Australia
- Westmoreland County, New South Wales
- the former name of Westmoreland Land District, Tasmania, Australia
- In Canada
- In the United Kingdom
- The county of Westmorland, archaically spelt Westmoreland.
- In the United States
- Westmoreland County, Pennsylvania
- Westmoreland County, Virginia
- Westmoreland County, Connecticut - A former county in Connecticut located in present-day Wyoming Valley