Population
| Pennsylvania State Data Center 2010 Population | 207,389 |
Washington County is ranked the third most populated county in Southwestern Pennsylvania.
Washington County has 242.0 persons per square mile.
Peters Township is the largest municipality in the County with a population of 20,345.
Pennsylvania State Data Center (PaSDC)
| Persons under 5 years old | 5.2% |
| Persons under 18 years old | 15.8% |
| Persons 65 years old and over | 17.4% |
| White persons | 94.8% |
| Black or African American persons | 3.2% |
| Persons reporting some other race | 2.0% |
| White persons, not of Hispanic/Latino origin | 94.8% |
| Persons of Hispanic or Latino origin | 0.9% |
Source Pennsylvania State Data Center (PaSDC)
