The Key West Express is a high-speed ferry service that travels between several locations in Florida (Fort Myers Beach, Marco Island, and Key West). Since these locations are all within the United States, you don't need a passport for this domestic travel.

For the majority of passengers, no, a passport is not strictly required to board the Key West Express ferry, provided you are a U.S. citizen. Since the ferry operates between Fort Myers or Marco Island and Key West—all of which are within the state of Florida—the journey is considered domestic travel. As of 2026, all passengers aged 18 and older must present a valid government-issued photo ID, such as a state driver's license. However, the company does list a passport as an acceptable form of ID. The only situation where a passport would be mandatory is for non-U.S. citizens, who must carry their valid foreign passport and any necessary visa documentation to comply with maritime security and Coast Guard regulations. For U.S. families, a birth certificate is often recommended for minors who do not yet have a photo ID, though requirements for children are generally more relaxed. Always ensure your ID is not expired, as the Key West Express follows strict TSA-style boarding protocols to ensure the safety of all passengers on the Gulf crossing.