A post-Khmer Rouge baby boom pushed the population above 10 million, although growth has slowed in recent years.

Infant mortality, for example, is twice as high among children whose mothers have no schooling compared to those with secondary or higher education (72 versus 31).

The greater longevity for females apparently reflected improved health practices during maternity and childbirth.

Source: UN World Population Prospects[15] The largest of the ethnic groups in Cambodia are the Khmer, who comprise 95.8% of the total population[4] in 2019 and primarily inhabit the lowland Mekong sub region and the central plains.

The Khmer historically have lived near the lower Mekong River in a contiguous arc that runs from the southern Khorat Plateau where modern-day Thailand, Laos and Cambodia meet in the northeast, stretching southwest through the lands surrounding Tonle Sap lake to the Cardamom Mountains, then continues back southeast to the mouth of the Mekong River in southeastern Vietnam.

The indigenous ethnic minorities, more commonly collectively referred to as the Khmer Loeu ("upland Khmer"), constitute the majority in the remote mountainous provinces of Ratanakiri, Mondulkiri and Stung Treng and are present in substantial numbers in Kratie Province.

Two of these highland groups, the Rade and the Jarai, are Chamic peoples who speak Austronesian languages descended from ancient Cham.

These indigenous ethnic minorities haven't integrated into Khmer culture and follow their traditional animist beliefs.

Tai peoples in Cambodia include the Lao along the Mekong at the northeast border, Thai (urban and rural), and the culturally Burmese Kola, who have visibly influenced the culture of Pailin Province.

Other Austroasiatic languages of Cambodia include Kuy, Por (Pear), Somray, Chong, Suoy, Sa'och, Tampuan, Kaco', Stieng, Mnong, Brao, Krung (Rade), and Sou (Laven).

[19] Non-Austroasiatic minority languages of Cambodia include Cham, and Jarai, (Austronesian) as well as Thai and Lao (Tai-Kadai).

Countries with notable populations of Cambodians are: This article incorporates public domain material from The World Factbook (2025 ed.).