Washington is a city in Washington County, Pennsylvania, United States, and part of the Pittsburgh Metro Area. The population was 13,663 at the 2010 census. It is the county seat of Washington County and is located in the southwestern part of the state. According to the United States Census Bureau, the city has a total area of 3.3square miles (8.5Square kilometers), all land.The Washington Wild Things minor league baseball team play at CONSOL Energy Park, constructed in 2002 in nearby North Franklin Township. The Wild Things are in the Frontier League, an independent professional baseball organization. Over their young history, the team has had considerable success, including a league-record 62 wins in 2004. As of the census of 2000, there were 15,268 people, 6,259 households, and 3,486families residing in the city. The population density was 5,199.2people per square mile (2,005.1Square kilometers). There were 7,111housing units at an average density of 2,421.5per square mile (933.9Square kilometers).