New York State Route 15A (NY 15A) is a north–south state highway located in the western portion of New York in the United States. It serves as an easterly alternate route of NY 15, beginning in the Livingston County town of Springwater and ending to the north in the Monroe County city of Rochester. NY 15A meets U.S. Route 20A (US 20A) in the hamlet of Hemlock, US 20 and NY 5 in the village of Lima, and Interstate 390 (I-390) twice in Henrietta and Brighton. Its southern and middle sections traverse mostly rural areas, while the northernmost piece in Henrietta, Brighton, and Rochester passes through significantly more developed areas.