Thomas is part of the USVI, so US citizens traveling directly from a US location won't need a passport. The same rules apply to St. Croix and St. John, the other main islands in the USVI, as well as Puerto Rico and the Spanish Virgin Islands Culebra and Vieques.

Yes, U.S. citizens can fly to St. Thomas (and the other U.S. Virgin Islands) without a passport, as it is a U.S. territory. Traveling from the U.S. mainland to St. Thomas is treated similarly to a domestic flight; you only need a valid government-issued photo ID, such as a driver's license. However, starting May 7, 2025, your driver's license must be REAL ID-compliant to be used for boarding. While a passport is not required for entry, it is highly recommended if you plan on "island hopping" to the nearby British Virgin Islands (BVI), which do require a passport for all visitors. It is also important to note that while you don't go through customs when arriving in St. Thomas, there is a U.S. Customs and Border Protection checkpoint when you depart the islands back to the mainland. For this reason, bringing a copy of your birth certificate for minors is a wise precaution to prove citizenship. For non-U.S. citizens, a valid passport and potentially a visa are still mandatory for travel to the U.S. Virgin Islands just as they would be for any other part of the United States.