Family name Phetthai (Phetthai 
) , across the world, is a very rare surname. The family name Phetthai is habitual in South-eastern Asia, particularly Thailand, where it is a very rare surname, and Malaysia. Much less frequently, Phetthai is the forename as well as the last name.
Aree, Supakchanat, Thammanoon, Jiratchaya, Wuttipong, Naphaphach, Fuangphet, Nutchaya, Nattawat, Kanyarat, Apichaya, Ekkapoom, Nongyao, Thusporn, Priwan, Boston, Parinyaporn, and Patcharaporn