New York State Route 320 (NY 320) is an east–west state highway located within Chenango County in the central part of New York in the United States. The western terminus of the route is at an intersection with NY 12 immediately north of the city of Norwich in the surrounding town of Norwich. Its eastern terminus is at Tiffany Road in North Norwich, where it continues northeast as County Route 29 (CR 29). NY 320 was assigned as part of the 1930 renumbering of state highways in New York.

Route 320 begins at an intersection with NY 12 in Norwich. The highway heads eastward, passing small businesses, and crosses over a river. Just after the river, Route 320 passes a suburbanized area, with businesses and homes surrounding the highway for a short distance. As the road leaves Norwich, it intersects with CR 32, where then the highway becomes a rural road, with houses leading the way. As Route 320 heads to the northeast, a small forest begins to parallel to its south. The forest soon makes way for fields and farms, with the highway heading through rural parts of Chenango County. At the intersection with Tiffany Road, Route 320 ends and the highway becomes CR 29.

CR 29 heads through more rural regions of Chenango County, intersecting with local roads that are surrounded by trees and farms. After passing through Kings Settlement, the highway turns northward towards New Berlin. For a while, there is nothing around the highway until the intersection with CR 28. CR 29 heads past a small lake and homes begin to return around the highway. The highway then turns to the southeast, intersecting with local roads and enters the area of New Berlin. There it becomes known as West Street.

In New Berlin, CR 29 enters the downtown area and terminates at an intersection with NY 8 and NY 80. West Street continues as NY 80 east.

NY 320 was assigned as part of the 1930 renumbering of state highways in New York and has not been substantially altered since that time. In 2005, the entirety of the 8.56-mile (13.78 km) CR 29 was repaved.

The entire route is in Chenango County.