The Xalbal River is a river of Guatemala. Its sources are located in the Sierra de los Cuchumatanes (at ) in the department of El Quiché, where the river is called Río Xaclbal or Río Chajul. The Xaclbal river flows northwards down the tropical lowlands of Ixcan where it is called Río Xalbal (at ), and crosses the border with Mexico, where it joins the Lacantún River, a tributary of the Usumacinta river. The Guatemalan part of Xaclbal river basin covers an area of 1,366 km2.