Sand Lake is a town in south-central part of Rensselaer County, New York, United States. Sand Lake is about 13 miles east of Albany, New York. As of the 2020 census, the population was 8,348. Within the town are three hamlets: Averill Park, Glass Lake and the hamlet of Sand Lake. Its four lakes are a source of recreation. Many commercial enterprises of the 19th century and into the 20th century relied on power generated from the Wynants Kill Creek and Burden Lake mills. The area is known for its fertile soil for grazing and agriculture.

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.