The Kensico Dam is a stonework dam located in Valhallal, New York. The dam holds the Kensico Reservoir which is the southernmost reservoir in New York City's water supply system.

The original Kensico Dam was a much smaller earth dam built in 1885. Several buildings in the village of Kensico had to be flooded to create the dam. In 1917 the new dam was completed and the entire of village of Kensico was flooded under 100 feet of water.

The dam is 300 feet high and 1830 feet long. The park at the foot of the dam called the Kensico Dam Plaza and you can go ice skating there in the winter.