The island is shared by Currituck County, North Carolina and Virginia Beach, Virginia, United States, bounded by the Currituck Sound, North Landing River, Back Bay, and Knotts Island Bay. Knotts Island is home to Mackay Island National Wildlife Refuge.
The island, which spans across Currituck County, North Carolina and Virginia Beach, Virginia, United States, is surrounded by the Currituck Sound, North Landing River, Back Bay, and Knotts Island Bay. Within this area lies Mackay Island National Wildlife Refuge on Knotts Island.