The land actually was part of Caladesi Island immediately to the south until a 1921 hurricane sheared the northern end into its own barrier island. The inlet there is now called, appropriately enough, Hurricane Pass.
Locals referred to the area first as Sand Island and then Hog Island until a developer set up thatched huts in 1939 and billed it as a destination for newlyweds. No one lives on the Gulf beach now, but Honeymoon Island currently enjoys its designation as a state park (there are some condo buildings before the entrance to the park). The island drew about 1.5 million visitors in the last year, making it a perennial favorite to top state park attendance lists.
The park includes places to eat and resupply your beach gear, plus some eco-lessons for curious visitors, but also features great hiking and paddling opportunities. There's also a dog-friendly beach on the south end of the island, for people willing to hit the trails.
Plan your trip
Tampa Bay is served by two airports, Tampa International Airport (TPA) in Hillsborough County and St. Pete-Clearwater International Airport (PIE) in Pinellas County. Multiple carriers service TPA, while most flights to and from PIE are run by Allegiant. There are many ground transportation options at both airports.
You could conceivably use a ride-sharing service and be dropped off at the admission gate, but distances are far and pickup would require some coordination.
The Pinellas Suncoast Transit Authority does not offer service across the Dunedin Causeway, but does maintain a route along Bayshore Boulevard in Dunedin on the mainland. The Jolley Trolley, which helps cart people between Tarpon Springs and Clearwater, also runs along Bayshore. A schedule and details are here.
This is one destination where this is the easy part, because the island has ample parking once you get inside the gate. There are hundreds of spaces for both the northern and southern ends of the beach. Since you already paid an entrance fee, there are no meters. There also is parking near the pavilions, plus several places to park along the road in case the park is really busy.