Cognomen Wonghajak (Wonghajak 
) , in the world, is a rare family name. The cognomen Wonghajak is characteristic of South-eastern Asia, particularly Thailand, where it is a rare surname.
Pairin, Auttapornchai, Nuttaporn, Nattaporn, Ratchanee, Phitsamai, Pacharaaon, Kamonchat, Saengchan, Wilailuk, Wilailak, Traiphop, Kunlanat, Worawut, Witawat, Neramit, Thitima, Jularat, Jaruwan, Lamphun, Kanokon, Supansa, Saranya, Orapan, Numfon, Disaya, Thanyamash, and Narongchai