Last name ฤทธิฤกษ์ (ฤทธิฤกษ์ 
, Rittiruek , Ritthiroek) , in the entire world, is a very rare family name. The cognomen ฤทธิฤกษ์ is habitual in South-eastern Asia, particularly Thailand, where it is a rare surname. Likewise, ฤทธิฤกษ์ is the forename as well as the last name.