Thái Bình river (Vietnamese: Sông Thái Bình) is the name of Thai Binh river system's main river in Northern Vietnam. This river system joining with Red river system have brought alluvium to create Red River Delta.
Thai Binh river starts in the area of Dong Phuc commune, Yen Dung district, Bac Giang province - where Thuong river and Cau river join with each other. It then flows to Hai Duong province and becomes the boundary between Bac Giang and Hai Duong. After flowing through the area of Hai Duong, it enters Thai Binh province and flows to the South China Sea at Ba Lat river mouth.
The total length of the main river is about 100 km (62 mi)