Altona is a town in Clinton County, New York, United States.

Archeological studies have found that by 1300 CE, the St. Lawrence Iroquoians, a distinct group who spoke the Laurentian language, built fortified villages similar to those visited and described by explorer Jacques Cartier in the mid-16th century.

They are believed to have been pushed out and defeated later in that century by the Mohawk, one of the Five Nations of the Iroquois Confederacy.

The first European-American settler arrived circa 1800, after the American Revolution, when New York attracted migrants from New England.

The early economy was based on natural resources: mining, logging, and tanning.

New York State Route 190 (Military Turnpike) is a northwest–southeast highway in the town.