Compatibility summary
Your Thailand plug may fit in Saint Kitts and Nevis outlets, as both use at least one common plug type.
Plug comparison
Thailand plug types: A B C O
Saint Kitts and Nevis plug types: A B G
Both countries share at least one plug type (A B C O and A B G), so some plugs may work without an adapter. Check your appliance.
Voltage comparison
Thailand: 220V, 50Hz
Saint Kitts and Nevis: 230V, 60Hz
Voltage difference is within a range many devices tolerate; check your appliance label.