Family name Longthong (Longthong 
, ลงทอง ) , across the world, is a rare cognomen. The last name Longthong is characteristic of South-eastern Asia, particularly Thailand, where it is a rare surname. Very seldom, Longthong is the forename as well as the last name.
Supat, Sittitep, Siwatchai, Supannee, Srinakorn, Amatawan, Apichart, Chatchai, Piyanuch, Piyachat, Phongkit, Ruangchai, Nathawat, Neatchanok, Waraporn, Yupaporn, Chatrapee, Chirachot, Kiattinan, Patcharin, Pramahadenpong, Phongphan, Saranwit, Umaporn, Visarut, Niramon, Supap, Panee, Seksan, Anuwut, Atiwit, Bontam, Kontee, Piched, Nattee, Namfon, Phongphun, Wichan, Bunreun, Pakawat, Piyawan, Phailin, Pheraya, Pusadee, Denphong, Darunee, Naramol, Natinee, Sasikan, and Thanaporn