Grafton is a town in Rensselaer County, New York, United States. The population was 2,051 at the 2020 census. It is believed that the town received its name from Grafton, Vermont, where the first town supervisor, Nathaniel Dumbleton, was originally from. The town is an interior town near the north-central part of the county. NY Route 2 passes across the town.

Rensselaer County is a county in the U.S. state of New York. As of the 2020 census, the population was 161,130. Its county seat is Troy. The county is named in honor of the family of Kiliaen van Rensselaer, the original Dutch owner of the land in the area. The county is part of the Capital District region of the state.