Family name ฤทธิ (Power 
, Ritti 
, ฤทธิ 
) , in the entire world, is a common last name. The cognomen ฤทธิ is habitual in Ireland, where it is a common surname, Guernsey, where it is quite a common surname, and Australia (explore the name in all countries). In absolute terms, the name is most common in the United States, the United Kingdom, and India. Much less frequently, ฤทธิ is the forename as well as the last name.