Guilderland is a town in Albany County, New York, United States. In the 2020 census, the town had a population of 36,848. The town is named for the Gelderland province in the Netherlands. The town of Guilderland is on the central-northwest border of the county. It is just west of Albany, the capital of the U.S. state of New York.

Albany County is a county in the state of New York, United States. Its northern border is formed by the Mohawk River, at its confluence with the Hudson River, which is to the east. As of the 2020 United States Census, the population was 314,848. The county seat and largest city is Albany, which is also the state capital of New York. As originally established by the English government in the colonial era, Albany County had an indefinite amount of land, but has had an area of 530 square miles (1,400 km2) since March 3, 1888. The county is named for the Duke of York and of Albany, who became James II of England. The county is part of the Capital District region of the state.