Cognomen Muangjai (Muangjai 
) , in all the world, is a rare surname. The cognomen Muangjai is characteristic of South-eastern Asia, particularly Thailand, where it is a rare surname. Much less frequently, Muangjai is the forename as well as the last name.
Anak, Ammarad, Ammared, Chanita, Perapon, Phaphorn, Janjira, Jenjira, Tuntipa, Vichain, Orathai, Wasupon, Utumpon, Kanyarat, Kraisorn, Parichat, Phakaporn, Rattapon, Ruttikal, Jinnanut, Tippawan, Nawaphon, Saifhon, Sansern, Montree, Wasana, Ampa, Renu, Sunee, Araya, Linda, Narin, Warin, Wijai, Yupin, Metiya, Wittawat, Sangad, Suputcha, Aranya, Akkara, Apiluck, Patima, Panida, Pakpum, Pranee, Jaroen, Nathan, Sunisa, and Worrarut