Last name ฤทธิวัฒน์ (ฤทธิวัฒน์ 
, Rithiwat , Rhittiwat ) , in the world, is an extremely rare family name. The cognomen ฤทธิวัฒน์ is habitual in South-eastern Asia, particularly Thailand, where it is an extremely rare surname. More frequently, ฤทธิวัฒน์ is the forename as well as the last name.