Cognomen Pairach (ไพรัช 
, Pairach 
) , in all the world, is a very rare last name. The surname Pairach is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare surname. Much more frequently, Pairach is the forename as well as the last name.
Anong, Usamanont, Maekhaapirak, Sanongchat, Khemmarat, Kitworawut, Pookcharoen, Piboonrungroj, Triranurat, Horthongrung, Samantrakul, Sophonprapaiwong, Chantanusart, Panchatree, Jantarakairoj, Jarernthai, Tipayachan, Kaewpradist, Rattanapong, Chainimitwatana, Kaewsangthong, Pattanachaiwit, Inchaiwong, Farweroj, Tangkool, Srithong, Saenar, Sekteera, Kaewin, Kumkua, Pairoh, Tubsuwan, Farwaeroj, Yimneum, Siwijarn, Alnahdi, Jongsirivanich, Anusorn, Koomyou, Panodpia, Pilaikiat, Pholput, Pungsup, Limkeaitsathaporn, Jarusan, Mameekage, Muankhae, Soonwera, Comsukorn, and Charoenchaipong