Manassas (; formerly Manassas Junction) is an independent city in the Commonwealth of Virginia. As of the 2010 census, the population was 37,821. The city borders Prince William County, and the independent city of Manassas Park, Virginia. The Bureau of Economic Analysis includes both Manassas and Manassas Park with Prince William County for statistical purposes.
Manassas also serves as the seat of Prince William County. It surrounds the 38-acre (150,000 m2) county courthouse, but that county property is not part of the city. The City of Manassas has several important historic sites from the period 1850–1870.
The City of Manassas is part of the Washington-Arlington-Alexandria, DC-VA-MD-WV Metropolitan Statistical Area and is in the Northern Virginia region.
In July 1861, the First Battle of Manassas—also known as the First Battle of Bull Run—was fought nearby, the first major land battle of the American Civil War. Manassas commemorated the 150th anniversary of the First Battle of Manassas on July 21–24, 2011.
The Second Battle of Manassas (or the Second Battle of Bull Run) was fought near Manassas on August 28–30, 1862.