Originating in northern Vietnam, the Vietnamese people pushed southward over two millennia to occupy the entire eastern seacoast of the Indochinese Peninsula.

In 1978–79, some 450,000 ethnic Chinese left Vietnam by boat as refugees (many officially encouraged and assisted) or were expelled across the land border with China.

In recent years the government has performed an about turn and is encouraging overseas Hoa to return and invest, but the ethnic Chinese population has been in continuous decline since the 1970s due to assimilation and low birth rates.

Other minority groups include the Cham—remnants of the once-mighty Champa Kingdom, conquered by the Vietnamese in the 15th century, Hmong, and Thái.

In the early 21st century, around another four million Vietnamese speakers are found outside of Vietnam, mostly refugees from the Vietnam-American War.

Vietnamese was heavily influenced by Chinese, with up to around 50–70% words having Chinese origins, whilst Khmer was heavily influenced by Sanskrit and Pali, uses a abugida writing system, and has a great part of its vocabulary originating from Indian languages.