Cadyville is a hamlet (and census-designated place) in Clinton County, New York, United States. As of the 2020 census, Cadyville had a population of 479. The community is located along the Saranac River and New York State Route 374, west of Plattsburgh. Cadyville has a post office with ZIP code 12918, which opened on July 25, 1840.
The school district is Saranac Central School District.