The Bang Pakong (Thai: แม่น้ำบางปะกง, pronounced [baːŋ pa.koŋ]) is a river in east Thailand. The river originates at the confluence of the Nakhon Nayok River and the Prachinburi River at Pak Nam Yothaka in Amphoe Ban Sang, Prachinburi Province. It empties into the Gulf of Thailand in the northeastern tip of the Bay of Bangkok. The watershed of the Bang Pa Kong is about 17,000 km².