Yes, if you are a U.S. citizen, you do not need a passport to go to Key West. Since Key West is part of the state of Florida, traveling there from any other U.S. state is considered a domestic trip. You only need a standard government-issued photo ID, such as a driver's license, to board a flight or drive across the Overseas Highway. In 2026, the REAL ID requirement is in full effect, so ensure your driver's license is REAL ID-compliant if you are using it for air travel. Even if you arrive via a cruise ship that departs and returns to a U.S. port (a "closed-loop" cruise), U.S. citizens can typically use a birth certificate and government ID instead of a passport, though a passport is always recommended for emergencies. For international travelers, the standard visa or ESTA requirements for entry into the United States apply, as Key West is an official port of entry with its own international airport (EYW).