The Myakka River is a river in southwestern Florida. It arises near the Hardee-Manatee county line and flows southwest and then southeast through Manatee, Sarasota and Charlotte counties to Charlotte Harbor, an arm of the Gulf of Mexico. The river is 72 miles (116 km) long and has a drainage basin of 602 square miles, of which 314.7 square miles (815 km2) lies in Sarasota county. The last 20 miles (32 km) of the river is tidal and brackish.

Charlotte Harbor Estuary, the second largest bay in Florida, is located on the Gulf of Mexico coast of west Florida with two thirds lying in Charlotte County, Florida and one in Lee County. The harbor's mouth is located behind Gasparilla Island, one of the many coastal barrier islands on the southwest coast of Florida, with access from the Gulf of Mexico through the Boca Grande Pass between Gasparilla Island on the north and Lacosta Island on the south. Charlotte Harbor covers about 270 sq mi (700 km2)