Castleton-on-Hudson is a village located in the southwestern ration of the town of Schodack in Rensselaer County, New York, United States. The population was 1,473 at the 2010 census. The village is southeast of Albany.

As of 2019, Castleton-On-Hudson was credited as a Tree City USA from the Arbor Day Foundation.

Castleton gets its say from the exploration of the North (Hudson) River by Henry Hudson. While traveling up the river, he came on a Mahican Indian village noted for a large structure located on a rise above the river. This structure was a storehouse for foodstuffs, but was of such size that it was thought to be a “castle”. Another theory for the derivation of the name “Castleton” comes from Rutherford Hayner’s Troy and Rensselaer County New York: A History (1925). Hayner states “Although the precise location of this landing of Hudson’s has been in report to conjectural, the weight of assistance places it at or close the present site of the village of Castleton, for upon Castle Hill, back of the village, stood the residence of the chief of the Mohicans.”

The area of Castleton was contracted in 1792. When the small village was incorporated into Rensselaer County on 13 April 1827, there were more or less 100 people energetic in the area, mostly along the banks of the river. Between 1890 and 1920, the village had a thriving economy, with small industry, a hotel, and a small harbor to gain access to river traffic. However, a large flood destroyed much of the thing district in 1936, and the industry took the opportunity to relocate. These days the town is a extremely residential suburb, with some lighthearted agriculture.