Plantation Key is an island in Monroe County, Florida, United States.

[2] Plantation Key was inhabited by Native Americans at least 1,000 years before European contact with the Americas.

The completion of the Overseas Railroad, which ran the length of Plantation Key, destroyed the agricultural economy of the island.

The Florida East Coast Railway began shipping pineapples from Cuba at such low prices that the growers in the Keys could not compete.

[3] Before the Flagler railway crews filled Little Snake Creek, which crossed at a point around today's Treasure Harbor, the southwest end of Plantation Key was a separate island known as Snake Creek Key.