Lake Jackson is an unincorporated community in Prince William County, just southeast of Manassas, Virginia. It lies on Lake Jackson (38°41′56″N77°27′10″W), a reservoir that was created by the Lake Jackson Dam (38°42′18″N77°26′53″W), on the Occoquan River. The dam was created in 1927 by Charles W. Alpaugh. The community, the lake, and the dam are all located in suburban Prince William County.