Family name Niwatchai (Niwatchai 
) , around the world, is a very rare cognomen. The last name Niwatchai is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare surname. More prevalently, Niwatchai is the forename as well as the last name.
Titla, Palakawong, Chaichang, Atsawamet, Sombatmak, Yiamsombat, Thainant, Gasemmongkol, Kamonjan, Boongodpetch, Bourthong, Chaikaew, Mahachai, Jaikham, Khearnkun, Khampee, Bhummaphan, Sarasri, Raksakaew, and Prasertdhanakul