Cognomen Ridtichai (Ridtichai 
) , around the globe, is an extremely rare last name. The cognomen Ridtichai is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare surname. More prevalently, Ridtichai is the forename as well as the last name.
Sennok, Rachai, Nayiam, Borseen, Sappasri, Thongkum, Tipkonglad, Wongsagul, and Chonrattanacheewin