Family name พลอยฤทธิ์ (พลอยฤทธิ์ 
) , worldwide, is a very rare cognomen. The surname พลอยฤทธิ์ is habitual in South-eastern Asia, particularly Thailand, where it is a very rare surname. Likewise, พลอยฤทธิ์ is the forename as well as the last name.