Mechanicville is a city in Saratoga County, New York, United States. The population was 5,163 at the 2020 census, a small decrease from 5,196 in 2010. It is the smallest city by area in the state. The name is derived from the occupations of early residents. The city is located on the eastern border of Saratoga County and is north of Albany, the state capital. Mechanicville borders the towns of Stillwater and Halfmoon in the county, and the town of Schaghticoke, Rensselaer County.