State Road 566 (SR 566) is an approximate one-mile-long (1.6 km), northwest-southeast highway near Plant City, Florida that connects Interstate 4 (I-4) to U.S. Route 92 (US 92).

State Road 566 enters Plant City and intersects Interstate 4.

The road continues east through Plant City as a four-lane divided highway and ends at the intersection of U.S. Route 92 across from the intersection with Berryfest Place west of Downtown Plant City, Florida.

Thonotosassa Road itself continues southeast of the route's eastern terminus, first as a frontage road on the north side of US 92 between SR 566 and Mobley Street, and then serves as the beginning of the one-way pairing of US 92 carrying eastbound US 92 until the intersection of Reynolds Road, which continues eastbound US 92 through the city.

The entire route is in Plant City, Hillsborough County.