Family name Niyomthai (Niyomthai 
) , across the world, is a rare last name. The last name Niyomthai is habitual in Thailand, where it is a rare surname, and the United States, where it is an extremely rare surname. Much less frequently, Niyomthai is the forename as well as the last name.
Pan, Metarida, Shindha, Supansa, Suwadee, Somchit, Arunsri, Apichai, Kanjana, Korawee, Krishna, Parinya, Panlaka, Praetara, Poonsuk, Puggamas, Rinrada, Janjira, Jakkrit, Jutamas, Jirapat, Thitita, Maneeya, Manopat, Virada, Niphon, Nit, Arch, Nara, Nipa, Nora, Fonn, Manop, Saneh, Sarun, Suwat, Nararat, Amita, Nikon, Virot, Sunant, Bundit, Panida, Rachin, Lersak, Taspawee, Thanet, Trirat, Pitak, and Natinee