List of highways numbered 18A

Canada

• Prince [Edward Island Route 18A]

United States

• County Road 18A (Union County, Florida)
• Nebraska Spur 18A
• Nevada [State Route 18A]
• New [York State Route 18A]
• * County Route 18A (Otsego County, New York)
• * County Route 18A (Washington County, New York)
• Oklahoma [State Highway 18A]