New York State Route 324 (NY 324) is an east–west state highway located in the western portion of New York in the United States. Officially, NY 324 begins at NY 384 in Niagara Falls and overlaps Interstate 190 (I-190, the Niagara Section of the New York State Thruway) south to Grand Island, where it separates from I-190 and continues southward as Grand Island Boulevard. As signed, however, NY 324 begins at the southern end of the official overlap and is contained entirely within Erie County. At the southern edge of Grand Island, NY 324 joins I-190 to cross over to the mainland, where it runs due east across three towns before reaching its eastern end at a junction with NY 5 in the town of Clarence.