Cognomen Onin (Onin 
, อรอินทร์ , อรอินทุ์ ) , around the globe, is quite a rare surname. The cognomen Onin is habitual in South-eastern Asia, particularly Thailand, where it is quite a rare surname, Philippines, where it is a rare surname, and Malaysia. Not in comparison with a country's population, it is commonest in Thailand, Philippines, and Russia. Also, Onin is the forename as well as the last name.