Cognomen Thirarat (ธีรารัตน์ 
, Thirarat 
, ธีรราช ) , globally, is a very rare family name. The family name Thirarat is habitual in South-eastern Asia, particularly Thailand, where it is a very rare surname. Much more prevalently, Thirarat is the forename as well as the last name.
Samma, Khunjaroen, Khuansaman, Klaiprasit, Poolvoraluck, Phunthong, Fungfuang, Uyasittharak, Saengthabthim, Songpracha, Chomthong, Srikhongchan, Kaewchamnong, Phutthawong, Ronghankaew, Rungthiratanaphaisan, Janjariyanon, Thongkrachang, Rattanawisutamon, Watcharinporn, Phutthachatkun, Choychanchaikul, Lertcharoenpob, Srisuksai, Orachorn, Sakhon, Saelim, Sukdee, Apiwan, Boonha, Yimyen, Poonpussorn, Rakdang, Rukdang, Sirisawat, Laykram, Tangjit, Hatthiya, Yoosawad, Yoosawat, Kunlasut, Phuethiamornsinchai, Julewanlee, Taengwichit, Nakakhong, Junsook, and Wiwattanakulrati