The Cross River Reservoir is a reservoir in the New York City water supply system located directly east and north of the northern Westchester County, New York, Hamlet of Katonah.

[2] Part of the system's Croton Watershed, it lies within the towns of Bedford, Lewisboro, and Pound Ridge, about 1 mile (1.6 km) east of the village of Katonah, and over 25 mi (40 km) north of New York City.

The reservoir is approximately 3.2 mi (5.1 km) long, has a drainage basin of 30 square miles (78 km2), and can hold 10.3 billion US gallons (39,000,000 m3) of water at full capacity, making it one of the city's smaller reservoirs.

To reach the city, water flows through Cross River into the Muscoot Reservoir, then down that one into the New Croton Reservoir, where it enters the New Croton Aqueduct in Yorktown.

Via the aqueduct, it flows into The Bronx, entering the Jerome Park Reservoir.