Cognomen ธัญญาวิทย์ (ธัญญาวิทย์ 
) , throughout the world, is an extremely rare family name. The last name ธัญญาวิทย์ is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare surname. More prevalently, ธัญญาวิทย์ is the forename as well as the last name.