Family name Ucy (Ucy 
) , around the world, is a rare cognomen. The cognomen Ucy is habitual in Indonesia, where it is a rare surname, Nigeria, where it is a very rare surname, and Thailand, where it is an extremely rare surname. Measured by absolute frequency, the name is most common in Indonesia, China, and Nigeria. More prevalently, Ucy is the forename as well as the last name.