Đông Bắc is the region to the north of the Red River Delta in Vietnam, bordering China. It is called Northeast to distinguish it from the Tây Bắc or "Northwest", but it is actually in the north and northeast of Hanoi, wider than Việt Bắc or "Northern Vietnam". The Northeast is one of three sub-regions of Northern Vietnam. Sometimes the Northeast includes the Red River Delta.

Cao Bằng is a province of the Northeast region of Vietnam. The province has borders with Hà Giang, Tuyên Quang, Bắc Kạn, and Lạng Sơn provinces within Vietnam. It also has a common international border with Guangxi province in China. The province covers 6,700.39 km2 (2,587.04 sq mi) and, as of 2019, its population was 530,341 people.