ACY is a three-letter acronym that may refer to:
- Atlantic City, New Jersey, a city in southern New Jersey known for its boardwalk and casinos.
- Atlantic City International Airport (IATA code: ACY) an airport in Egg Harbor Township that serves the Atlantic City area.
- Atlantic City Rail Terminal (Amtrak code: ACY), a railway station on New Jersey Transit's Atlantic City Line.
- Abercynon railway station (National Rail code: ACY), a railway station on the Merthyr Line in South Wales.
- Akron, Canton and Youngstown Railroad