The Commonwealth of Virginia grants certain powers to incorporated municipalities. There are seven towns in the County. Washington Dulles International Airport is also included due to its jurisdictional authority, but is not tracked by Loudoun's Management Information System (LMIS).

Town boundaries can define the limits of zoning, subdivision control limits, and other responsibilities of both the towns and the County. Jurisdictional authority is represented for each of the seven towns and Washington Dulles International Airport.