Family name Oijai (Oijai 
) , globally, is an extremely rare cognomen. The surname Oijai is characteristic of South-eastern Asia, particularly Thailand, where it is an extremely rare surname. Predominantly, Oijai is the forename as well as the last name.
Sone, Khongsumran, Lewanonchai, Groetsch, Kaewkrue, Chaiwong, Athiprom, Nonchot, Lertlam, Riabroi, Klinhom, Comtara, Somboon, Ongrai, Pimjong, Somjit, Wonok, Janto, Limpanyalert, and Likitpongsakul