Lai River may refer to:
Pakistan Lai Nullah, also Lai River, flowing from the Margalla Hills through Rawalpindi
Papua New Guinea Lai River (Purari) is a tributary of the Purari River in Southern Highlands Province in the central highlands Lai River (Sepik) is a tributary of the Sepik River in Enga Province in the central highlands
Thailand Nam Mae Lai is a tributary of the Yom River and part of the Chao Phraya River basin
Vietnam Ba Lai River in the Mekong Delta region Lai Giang River, known as the Lai River, in central Vietnam by Bồng Sơn