New York State Route 18 (NY 18) is an east–west state highway in western New York in the United States. It runs parallel to the south shore of Lake Ontario for most of its length between Niagara County and Monroe County. NY 18, which also passes through Orleans County, acts as a northerly alternate to NY 104, another east–west route that parallels NY 18 to the south on Ridge Road. The western terminus of NY 18 is at a complex grade-separated interchange with NY 104 outside the village of Lewiston. Its eastern terminus is at a junction with NY 104 in an area of Rochester known as Eastman Business Park.

Niagara County is in the U.S. state of New York. As of the 2020 census, the population was 212,666. The county seat is Lockport. The county name is from the Iroquois word Onguiaahra; meaning the strait or thunder of waters. The county is part of the Western New York region of the state.