is a town in Schenectady County, New York, United States. The population was 28,316 at the 2000 census.
is in the south-central part of the county. It was founded in the 1820s by Dutch settlers, who named it after the port of Rotterdam in the Netherlands, where many emigrants last touched European grounds. The town borders the City of Schenectady. Rotterdam is the headquarters of Price Chopper, a supermarket chain in Upstate New York and New England.
The Mohawk River defines the northeast town line. The New York State Thruway passes through the town.
According to the United States Census Bureau, the town has a total area of 36.5 square miles (94.5 km²), of which, 36.0 square miles (93.2 km²) of it is land and 0.5 square miles (1.3 km²) of it (1.40%) is water.