Surname Thoong (Thoong 
) , worldwide, is quite a rare family name. The family name Thoong is characteristic of Guernsey, where it is quite a common surname, Malaysia, where it is quite a rare surname, and Sweden, where it is a rare surname. In absolute terms, this name is the most popular in Malaysia, Vietnam, and the United States. Much less frequently, Thoong is the forename as well as the last name.