The Yuam River (Thai: แม่น้ำยวม is a river in northwestern Thailand, part of the Salween watershed. It originates in the mountains of the Thanon Thong Chai Range, Khun Yuam District, Mae Hong Son Province, Thailand. The river flows in a north–south direction and then in Sop Moei District it bends westwards and then northwestwards, forming a stretch of the Thai/Burmese border shortly before it joins the left bank of the Moei River, shortly before its confluence with the Salween.