Cognomen Sainui (Sainui 
) , in all the world, is a rare surname. The last name Sainui is characteristic of South-eastern Asia, particularly Thailand, where it is a rare surname.
Siwa, Sumalee, Aphirak, Charoen, Chaiyut, Kaithep, Kulnida, Phanisa, Ploilida, Rungtip, Jantana, Jarunee, Jirasak, Narudom, Warunee, Yonlada, Ubonrat, Munowwas, Surachai, Sutaporn, Anchalee, Kanchana, Supawat, Shaiyut, Vitoon, Haliya, Lali, Wapa, Munir, Sarif, Surin, Pinyo, Danai, Janya, Naret, Nicha, Paphawin, Haris, Wapha, Wijak, Marina, Mayura, Sunisa, Areeya, Prapat, Damiya, Lalita, Tatiya, Onuma, and Pornjeera