Chaliyar is the fourth longest river in Kerala and is also known as Beypore River in its lower reaches as it comes closer to the sea. The length of the river is 169 kilometers with a total drainage area of 2,923 sq km, of which 2,535 sq km is in Kerala and the rest in Tamil Nadu.

The Chaliyar originates in the Western Ghats range at Elambalari Hills, which is located near the town of Cherambadi in the Nilgiri district of Tamil Nadu. It flows through the Malappuram district and before entering the city of Kozhikode it forms a borderline between Malappuram district and Kozhikode district. It finally evacuates into the Arabian Sea. Some of the tributaries of the Chaliyar originate from Wayanad district and joins the main river in Malappuram. The important tributaries of the Chaliyar are Chalipuzha, Punnapuzha, Pandiyar, Karimpuzha, Vadapurampuzha, Iringipuzha and Iruthilpuzha.

The towns located on the towns of the river are Nilambur, Edavanna, Areekode, Cheruvadi, Mavoor, Peruvayal, Feroke and Beypore. A few kilometers away from the Kondotty Hill the Kavanakallu Regulator cum bridge is constructed over the Chaliyar River. Few kilometers from Nilambur, beyond the Chaliyar there is Valamthode.