Pahang River, river in Pahang region, West Malaysia (Malaya). It is the longest river on the Malay Peninsula. It rises in two headstreams, the Jelai and Tembeling, about 10 miles (16 km) north of Jerantut and flows south past Temerloh, paralleling the Main Range to Mengkarak, where, at the break of slope between the mountains and the plains, it abruptly turns eastward. The river then completes its 271-mile (436-kilometre) course, through alluvial plains more than 20 miles (32 km) wide, to empty into the South China Sea at Pekan.
Navigable upstream by shallow-draft boats for about 250 miles (400 km), the Pahang was a vital link in the porterage route between the Malay Peninsula’s east and west coasts during the 15th and 16th centuries. Settlers later moved upriver, establishing rubber and coconut plantations along its banks. Deforestation in the river’s basin has led to heavy flooding during the monsoon season (November–February).