State Road 518 (SR 518), also called Eau Gallie Boulevard, is a short but major east–west highway with a western terminus at Interstate 95 on the Florida mainland, crossing the Indian River via the Eau Gallie Causeway (and intersecting the southern end of SR 513), and having its eastern terminus at SR A1A.

State Road 518 begins at Exit 183 of I-95, and continues east on Eau Gallie Boulevard through a recently built suburban area.

At the east end of the causeway, it intersects State Road 513, entering Indian Harbour Beach.

It passes through more commercial developments for the rest of the route, where it ends at State Road A1A, just west of the beach and the Atlantic Ocean.

Upon the completion of West Eau Gallie Boulevard in the 1980s,[4] the sign for the I-95 exit to SR 518 changed the name of the street from "Sarno Road" to "Eau Gallie Boulevard" and SR 518 was re-routed to its current configuration.