List of highways numbered 18A

The following highways are numbered 18A:

Canada

 * PEI Highway 18A.svg Prince Edward Island Route 18A

United States

 * Union County 18A.svg County Road 18A (Union County, Florida)
 * N SPUR 18A.svg Nebraska Spur 18A
 * Nevada 18A.svg Nevada State Route 18A (former)
 * NY-18A (1960).svg New York State Route 18A (former)
 * Otsego County Route 18A NY.svg County Route 18A (Otsego County, New York)
 * Washington County Route 18A NY.svg County Route 18A (Washington County, New York)
 * Oklahoma State Highway 18A.svg Oklahoma State Highway 18A