New York State Route 9D (NY 9D) is a north–south state highway in the Hudson Valley region of New York in the United States. It starts at the eastern end of the Bear Mountain Bridge at an intersection with U.S. Route 6 (US 6) and US 202 in Westchester County, and follows the eastern shore of the Hudson River for 25.21 miles (40.57 km) to a junction with US 9 north of the village of Wappingers Falls in Dutchess County.