Cognomen Sileng (斯楞 
, Sileng 
, เงียบ 
) , in the world, is a very rare family name. The surname Sileng is characteristic of South-eastern Asia, particularly Philippines, where it is a very rare surname, Cambodia, and Thailand, where it is an extremely rare surname. Measured by absolute frequency, it is the most numerous in China, Philippines, and Cambodia. More frequently, Sileng is the forename as well as the last name.