Family name ฤทธิ์วงศ์ (ฤทธิ์วงศ์ 
) , across the world, is a very rare cognomen. The cognomen ฤทธิ์วงศ์ is habitual in South-eastern Asia, particularly Thailand, where it is a very rare surname. Much less frequently, ฤทธิ์วงศ์ is the forename as well as the last name.