Cortland is a city in Cortland County, New York, United States of America. Known as the Crown City, Cortland is in New York's Southern Tier region. As of the 2010 census it had a population of 19,204. It is the county seat of Cortland County. Largely in an agricultural area, with deep fertile valleys surrounded by high hills, the town is most famous for it's college. Interstate 81 winds around the northern edge of the village.