Washington is a city in and the county seat of Washington County, Pennsylvania, United States, within the Greater Pittsburgh Region in the southwestern part of the state. The population was 13,663 at the 2010 census.
Washington is home to Washington & Jefferson College and Pony League baseball.
According to the United States Census Bureau, Washington has a total area of 3.3 square miles (8.5 km2), all land.
Washington has a humid continental climate (Köppen Dfb), with warm summers and cold, snowy winters. Precipitation is highest in the summer months, with an annual average of 38.87 in (987 mm). Snow usually falls between November and April, with an average of 37.8 in (96 cm).
Washington has four borders, including East Washington to the east, South Strabane Township from the north to south-southeast, North Franklin Township from the south to southwest, and Canton Township from the west to northwest.
Delaware Indian chief Tangooqua, commonly known as "Catfish", had a camp on a branch of Chartiers Creek, in what is now part of the city of Washington. The French labeled the area "Wissameking", meaning "catfish place", as early as 1757. The area of Washington was settled by many immigrants from Scotland and the north of Ireland along with settlers from eastern and central parts of colonial Virginia.