The Bumbungan River (Tagalog: Ilog Bumbungan) is a river in the province of Laguna in the Philippines. It is commonly referred to as the Pagsanjan River because of the popularity of the municipality of Pagsanjan and Pagsanjan Falls, one of the province's tourist destinations. The municipality of Pagsanjan was named so because it is where the , originating from Mount Banahaw, joins the Bumbungan. Its old name, Pinagsangahan, which literally means branching, was changed to Pagsanjan during the Spanish Colonial Era.