Bahia Honda State Park, State park on Bahia Honda Key in Monroe County, Florida, US

Bahia Honda State Park covers 212 hectares on Bahia Honda Key, 19 km south of Marathon and west of the Seven Mile Bridge. The Overseas Highway (U.S. 1) crosses the island. The park lies where the limestone islands of the northeastern Keys meet the coral islands of the southwest, and its four kilometres of white-sand beaches include Calusa, Loggerhead and Sandspur.

Bahia Honda Key belonged to Henry Morrison Flagler's Florida East Coast Railway; the Old Bahia Honda Bridge, over 1.5 km long, was one of the costliest structures on the line because of water up to 12 m deep. After a new road bridge opened, part of the old bridge was removed in 1972 to ease boat traffic. The state park was founded in 1961 when Florida bought its first five hectares on the island.

The park serves as a resting point for migratory birds and wading birds passing through the region. Visitors encounter various species moving through the shallow waters and mangrove areas along the shoreline.

The park is most accessible during calm weather when water and wind conditions allow for snorkeling and boating activities. Visitors should arrive early to secure good spots and avoid the afternoon heat.

Part of the Old Bahia Honda Bridge was removed in 1972 to ease boat traffic, but the walkable section remains and gives visitors a panorama over the island and surrounding waters. The bridge was among the costliest structures of Flagler's railway because the water off the island reaches 12 metres deep.