New York State Route 635 (NY 635) is a state highway located in the vicinity of Syracuse in Onondaga County, New York, in the United States. It extends for 2.25 miles (3.62 km) along Thompson Road from an intersection with Erie Boulevard (NY 5) in Syracuse to Carrier Circle in DeWitt, where NY 635 connects to both the New York State Thruway (Interstate 90 or I-90) and NY 298. Along the way NY 635 also meets I-690. The route was assigned in 1980 after the section of Thompson Road between NY 290 and Carrier Circle was acquired by the state of New York.