Altona is a town in Clinton County, New York, United States. The population was 2,887 at the 2010 census. The town was named after the Altona, Hamburg district of Germany. The town contains a hamlet which is also called Altona.
The Town of Altona is centrally located in the county. The western part is inside the Adirondack Park boundary, but the entire town is specifically excluded from the park by statute. Altona is northwest of Plattsburgh, New York.
Close to the St. Lawrence River, the area was home to various cultures of indigenous peoples for thousands of years. Archeological studies have found that by 1300 CE, the St. Lawrence Iroquoians, a distinct group who spoke Laurentian, built fortified villages similar to those visited and described by explorer Jacques Cartier in the mid-16th century.