The Río Pantaleón is a river in the south of Guatemala. Its sources are located in the Sierra Madre range, on the western slopes of the Volcán de Fuego in the departments of Chimaltenango and Escuintla. The river flows in a south-westerly direction through the coastal lowlands of Escuintla where it joins the San Crostobal River, a tributary of the Coyolate River.