Surname Thitiyarat (ฐิติยารัตน์ 
, Thitiyarat , ฐิติญารัตน์ ) , across the world, is a very rare last name. The surname Thitiyarat is habitual in South-eastern Asia, particularly Thailand, where it is a very rare surname. More frequently, Thitiyarat is the forename as well as the last name.