Route 28A, or Highway 28A, may refer to:
Massachusetts Route 28A 
New Hampshire Route 28A 
County Route 28A (Monmouth County, New Jersey) 
New York State Route 28A 
Oklahoma State Highway 28A 
New York State Route 28 (NY 28) is a state highway extending for 281.69 miles (453.34 km) in the shape of a "C" between the Hudson Valley city of Kingston and southern Warren County in the U.S. state of New York. Along the way, it intersects several major routes, including Interstate 88 (I-88), U.S. Route 20 (US 20), and the New York State Thruway twice. The southern terminus of NY 28 is at NY 32 in Kingston and the northern terminus is at US 9 in Warrensburg. In Kingston, NY 28 is co-designated as Interstate 587 from its southern terminus at NY 32 to the roundabout linking it to the Thruway (I-87).
New Hampshire Route 28 is an 85.413-mile-long (137.459 km) north–south state highway in eastern New Hampshire. It connects the town of Ossipee in east-central New Hampshire with Salem on the Massachusetts border, while passing through Manchester, the largest city in the state.
New York State Route 28A (NY 28A) is an east–west state highway in Ulster County, New York, in the United States. It extends for nearly 20 miles (32 km) along the south side of Ashokan Reservoir in Catskill Park, serving as a southerly alternate route of NY 28 through the area. Many of the communities along its length, such as West Shokan and Olivebridge, are relocated versions of those condemned for the reservoir's construction. Near Olivebridge, NY 28A intersects NY 213, the only other state route that NY 28A intersects aside from its parent, NY 28.
