Cognomen ธารวิทย์ (Thanwit 
, Tharawit , ธารวิทย์ ) , around the world, is a very rare surname. The cognomen ธารวิทย์ is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare surname. More frequently, ธารวิทย์ is the forename as well as the last name.