New York State Route 423 (NY 423) is an east–west state highway located within the town of Stillwater in Saratoga County, New York, in the United States. It extends for 3.86 miles (6.21 km) from an intersection with NY 9P on the eastern shore of Saratoga Lake in the hamlet of Snake Hill to a junction with NY 32 southwest of Saratoga National Historic Park. The road was acquired by the state of New York in the early 1920s and designated as NY 423 in the early 1930s.