Last name รัตนเพ็ญ (รัตนเพ็ญ 
, Rattanaphen ) , in the world, is a very rare family name. The surname รัตนเพ็ญ is habitual in South-eastern Asia, particularly Thailand, where it is a very rare surname. Very seldom, รัตนเพ็ญ is the forename as well as the last name.