You need a voltage converter in Saint Lucia! You can find voltage converters at Amazon. Because you also need a power plug adapter, you should consider a combined plug adapter/voltage converter. Also the frequency in Saint Lucia (50 Hz) differs from the frequency in the United States of America (60 Hz).

To charge your phone in St. Lucia in 2026, you primarily need a Type G power adapter, which is the three-rectangular-pin plug used in the United Kingdom. The standard voltage in St. Lucia is 230V to 240V with a frequency of 50Hz. Fortunately, almost all modern smartphones (including iPhones and Androids) have "dual-voltage" chargers—look for "INPUT: 100-240V" printed on your charging brick. This means you do not need a voltage converter, just a physical plug adapter to fit the socket. If you are traveling from North America, where the standard is 110V, your phone will handle the 230V just fine, but larger appliances like hair dryers or curling irons may require a heavy-duty transformer or they will burn out. Most high-end resorts in St. Lucia now include "Universal" or US-style outlets near the bedside, but for smaller guesthouses or local stays, a Type G adapter is essential to keep your devices powered throughout your Caribbean vacation.