State Road 55 is mainly the internal or secret designation of U.S. Route 19 through Florida, although it has appeared on maps and atlases on several occasions. State Road 55 originates at the Georgia state line north of Ashville, and ends at SR 684 in Bradenton. North of Perry, it is the secret route for US 221, continuing north into Georgia as Georgia State Route 76. South of Memphis, it is a secret designation for US 41; it is also a secret designation for US 301 in the Bradenton - Palmetto area, along a segment co-signed with US 41.

U.S. Highway 19 (US 19) runs about 262 miles (422 km) along Florida's west coast from an interchange with US 41 in Memphis, south of Tampa, and continues to the Georgia border north of Monticello.