List of highways numbered 100A

The following highways are numbered 100A:

United States

 * Bradford County 100A.svg County Road 100A (Bradford County, Florida)
 * Columbia County 100A.svg County Road 100A (Columbia County, Florida)
 * Union County 100A.svg County Road 100A (Union County, Florida)
 * MA Route 100A.svg Maine State Route 100A
 * NY-100A.svg New York State Route 100A
 * Vermont 100A.svg Vermont Route 100A