Hailesboro is a hamlet and census-designated place in St. Lawrence County, New York, United States located in the town of Fowler. As of the 2020 census, Hailesboro had a population of 544. Hailesboro has a post office with ZIP code 13645. New York State Route 58 and New York State Route 812 pass through the community.
According to the U.S. Census Bureau, the community has an area of ; of its area is land, and is water.
The census-designated place is in the Gouverneur Central School District.