Family name Ratchai (Ratchai 
, รัชชัย , รัตน์ชัย ) , all over the world, is a rare cognomen. The family name Ratchai is habitual in South-eastern Asia, particularly Thailand, where it is a rare surname. More prevalently, Ratchai is the forename as well as the last name.
Sony, Rujiwipatna, Duangploy, Thumprapa, Sirisuwanjinda, Sungworavit, Choeipratoom, Boonsathorn, Khiewngamdee, Pichayapoom, Wongisariyakul, Yeangyongpan, Suksanguankit, Chansongserm, Panyachatporn, Damnoenkittikun, Phiromkit, Bhattarapornlert, Pattravinid, Chacuttri, Bunnag, Laomelee, Chaisri, Kiatmata, Junaksorn, Nakmueang, Fungklin, Sornsuwan, Kongquet, Putiwattanachai, Ratmunikanon, Duangwiboon, Leethochawalit, Satheainpattanakul, Srisodsai, Kaeosomnuek, and Puranachaikeeree