Dorothea is a settlement on the island of Saint Thomas in the United States Virgin Islands. Saint Thomas is an Island in the Caribbean Sea, a County and constituent district of the United States Virgin Islands (USVI an unincorporated The United States Virgin Islands is a group of Islands in the Caribbean that are an Insular area of the United States. It is located to the northwest of the capital, Charlotte Amalie. Charlotte Amalie is the Capital and largest city of the US Virgin Islands.