The Saw Mill River is a 23.5-mile (37.8 km) tributary of the Hudson River in Westchester County, New York, United States. It flows from an unnamed pond north of Chappaqua to Getty Square in Yonkers, where it empties into the Hudson as that river's southernmost tributary. It is the only major stream in southern Westchester County to drain into the Hudson instead of Long Island Sound. It drains an area of 26.5 square miles (69 km2), most of it heavily developed suburbia. For 16 miles (26 km), it flows parallel to the Saw Mill River Parkway, a commuter artery, an association that has been said to give the river an "identity crisis."

Getty Square is the name for downtown Yonkers, New York, centered on the public square. Getty Square is the civic center, central business district, and transit hub of the City of Yonkers. A dense and growing residential area, it is located in southern Westchester County, New York. The square is named after prominent 19th-century merchant Robert Getty.