Last name Jongsu (종수 
, Jongsu 
) , worldwide, is a rare family name. The cognomen Jongsu is characteristic of South Korea, where it is a rare surname, Malaysia, where it is a very rare surname, and Vietnam, where it is an extremely rare surname. Measured by absolute frequency, this name is the most popular in South Korea, China, and Malaysia. Much more prevalently, Jongsu is the forename as well as the last name.