Florida State Road A1A

State Road A1A (SR A1A) is a north-south Florida State Road that runs mostly along the Atlantic Ocean, with sections from Key West at the southern tip of Florida, to Fernandina Beach, just south of Georgia on Amelia Island. It is the main road through most oceanfront towns. Part of SR A1A is designated the A1A Scenic and Historic Coastal Byway, a National Scenic Byway. A portion of A1A that passes through Volusia County is designated the Ormond Scenic Loop and Trail, a Florida Scenic Highway. It is also called the Indian River Lagoon Scenic Highway from State Road 510 at Wabasso Beach to U.S. Route 1 in Cocoa.

The designation is unique: other than SR A1A Alternate (now SR 811, CR 707, SR 732, and an extension of SR 842), only two other Florida state roads have begun with a letter: SR A19A (now a loop of SR 693-SR 699-SR 682 near St. Petersburg), and SR G1A (now SR 300).

The road was assigned the number 1 in the 1945 renumbering, mostly replacing the former State Road 140 designation. The number reflected its location in the new grid as the easternmost major north–south road. About a year and a half later, in November 1946, the State Road Board resolved to renumber the route due to confusion with the parallel U.S. Highway 1. The new designation, A1A, was chosen to keep the number 1 in its place in the grid.