ancient kingdom occupying much of what is now northern Vietnam and the southern Chinese provinces of Kwangtung and Kwangsi.

The kingdom was formed in 207 BC, during the breakup of the Ch'in dynasty (221–206 BC), when the Ch'in governor of Yüeh (now Kwangtung and Kwangsi provinces) declared his territory independent. His son Chao T'o (Trieu Da) expanded the new kingdom southward, incorporating the Red River delta and the area as far south as Da Nang.

Nam Viet, or Nan Yüeh (meaning “Southern Yüeh”), remained independent though loosely associated with the Han dynasty (founded 206 BC) until it was conquered by the Han emperor Wu Ti in 111 BC. Following the conquest, the area became a region for Chinese settlement, a policy that eventually resulted in the sinicization of Kwangtung and Kwangsi and introduced Chinese culture to northern Vietnam. The attempt to absorb Vietnam into China also engendered an increasing self-consciousness among the people of the northern and central regions of Vietnam.

In AD 939 the term Nam Viet appeared again as the name of the kingdom centred in the Red River valley at Co Loa. Ngo Quyen (q.v.) drove the Chinese out of the area and founded his own dynasty, which endured only until 954.

The term was revived again in 1802 by the emperor Gia Long but was inverted to Viet Nam.