Accomack County is a United States county located in the Eastern edge of the Commonwealth of Virginia. Together, Accomack and Northampton counties comprise the Eastern Shore of Virginia, which in turn is part of the Delmarva Peninsula, bordered by the Chesapeake Bay and the Atlantic Ocean. The Accomack county seat is the town of Accomac.The Eastern Shore of Virginia was formerly "Accomac Shire", until being renamed Northampton County in 1642.