St. Thomas is a U.S. territory, so U.S. citizens generally do not need a passport to travel there from the mainland United States. However, a valid passport is highly recommended. The airport is relatively small, and customs procedures can add time to your travel experience, particularly when departing the island.
If you plan to visit other nearby islands that are not U.S. territories, a valid passport will be required for entry. We recommend checking the entry requirements for each destination you plan to visit before your trip.