Sungai Kangsar is a river in Perak. A tributary of Sungai Perak, it is one of the major rivers in that state that does not flow directly into the sea. I have traced its route for some 19km from the foot of Gunung Bubu. It flows westward, south of Padang Rengas, to discharge into Sungai Perak at Kuala Kangsar, which is named after the river.