The Indian River is a 121-mile long brackish lagoon in Florida. It is part of the Indian River Lagoon system, which in turn forms part of the Atlantic Intracoastal Waterway. It was originally named Rio de Ais after the Ais Indian tribe, who lived along the east coast of Florida, but was later given its current name.
The Indian River extends southward from the Ponce de Leon inlet in New Smyrna Beach in Volusia County southward and across the Haulover Canal and along the western shore of Merritt Island. The Banana River flows into the Indian River on the island's south side. The Indian River continues southward to St. Lucie Inlet. At certain seasons of the year, bridges have tended to impede the flow of gracilaria, resulting in an odor of hydrogen sulfide in the area.