Across the world, Watchai (วัชชัย 
, Watchai , วัตน์ชัย ) is a very rare primarily masculine, but scarcely feminine first name. The first name Watchai is characteristic of South-eastern Asia, particularly Thailand, where it is a rare predominantly boy's, but very infrequently female name. Much less frequently, Watchai is the last name as well as the forename.
Srihawong, Weeradetsontonchai, Mongkolsrisawad, Weeradetsuntonchai, Weeradetsunthornchai, Weeradetsonthornchai, Nawapornchaimongkol, Jittirattavoon, Phansaraphum, Kaewpaluk, Chaitawat, Setthasuk, Mahaphaisan, Phothong, Ruerueang, Khotprom, Watcharintarachai, and Kanchanasirirat