Chinese Cambodians (or Sino-Khmers) are Cambodian citizens of Chinese ancestry or Chinese of full or partial Khmer ancestry. The Khmer term Khmer Kat Chen (ខ្មែរកាត់ចិន) is used for people of mixed Chinese and Khmer descent; Chen Khmer (ចិនខ្មែរ) means Cambodian-born citizen with ancestry from China. The Khmer constitute the largest ethnic group in Cambodia among whom Chen means "Chinese". Contact with the Chinese people such as envoys, merchants, travelers and diplomats who regularly visited Indochina verifiably existed since the beginning of the common era. However, the earliest record of a Chinese community in Cambodia dates to the 13th century.

Chinese Cambodians also play a leading role in Cambodia's business sector and dominate the Cambodian economy today. In addition, Chinese Cambodians have a strong presence in Cambodia's political scene with many high ranking government officials and much of the country's political elite being of Chinese ancestry.

The earliest records of Chinese settlement dates back to the late 13th century, where a detailed and comprehensive Record of Cambodia mentions the presence of Chinese businessmen trading at Angkor. Portuguese seafarers noted the presence of a small Chinese settlement in Phnom Penh in the early 17th century. Around the same time Lim To Khieng, a Chinese privateer, stayed in Cambodia while trading and conducting raids in the South China Sea. Shortly after the fall of the Ming dynasty in 1644, Chinese troops under the command of Mac Cuu and Duong Ngan Dich encouraged large numbers of refugees from Fujian and Guangdong provinces to settle in Indochina. The majority of the immigrants were men and boys who eventually married local Khmer women. Their descendants usually assimilated smoothly into the local communities, the economic and social process and personally identified as Cambodians. However, customs were also imported, such as the practice of the Chinese topknot that was practiced until the 18th century.

The French first introduced a legislation in 1873 which classified Chinese immigrants as 'Alien Asians' and subjects were subjected to resident taxes. King Norodom introduced a legislative reform in 1884 which required the Chinese immigrants to pay higher resident taxes but there were no legal restrictions imposed for immigrants to take up Cambodian citizenship. In 1891, the French introduced a legislation first introduced by Gia Long in Cochinchina, called "bang" in Chinese. Five associations were established in Cambodia, each identified by its specific region of ancestral origin in China; Cantonese, Hokkien, Hainanese, Teochew and Hakka. Chinese immigrants were required to register with their association to settle in Cambodia. Each of these associations was led by an elected headman, who would be responsible for maintaining law, order and tax collection duties from his countrymen.

The French system of administering the Chinese Cambodian community was terminated in 1958. During the 1960s, Chinese community affairs tended to be handled, at least in Phnom Penh, by the Chinese Hospital Committee, an organization set up to fund and to administer a hospital established earlier for the Chinese community.

This committee was the largest association of Chinese merchants in the country, and it was required by the organization's constitution to include on its fifteen-member board six people from the Teochew group, three from the Cantonese, two from the Hokkien, two from the Hakka, and two from the Hainanese. The hospital board constituted the recognized leadership of Phnom Penh's Chinese community. Local Chinese school boards in the smaller cities and towns often served a similar function.

This was to be a high point in terms of the rights of the Chinese minorities. Cambodian independence in 1953 saw a regression in their treatment by state authorities and the previously existing autonomy was eliminated by the new government. However, many private associations - cultural, business-oriented and to do with education - were simply continued by the Chinese communities and clan associations themselves, as these communities still had very significant economic and political power. Anti-Chinese feeling and policies emerged, however, after the coup of 1970 which saw the establishing of a pro-West government which considered the neighbouring People's Republic of China a dangerous threat - and the Chinese minorities in Cambodia as a possible fifth column.^{[citation needed]}

The year 1970 thus marks the beginning of almost two decades of severe repression of the Chinese minorities in Cambodia. It was after this point that Cambodian authorities started forcing the closure of Chinese schools and newspapers, requiring the Chinese to carry special identity papers, imposing special taxes on the Chinese and moving towards denying them Cambodian citizenship.^{[citation needed]} While the Khmer Rouge regime appeared to have a more ‘tolerant' ethnic policy initially, it continued to discriminate against the Chinese once it had completed its takeover of Cambodia.^{[citation needed]} The continued discrimination, however, now rested on class rather than ethnic grounds; since the majority of urban Chinese were traders, they were classified as ‘capitalists' by the revolutionary regime.^{[citation needed]} While there is no evidence that the Chinese were particularly targeted in the Khmer Rouge purges,^{[citation needed]} their population in Cambodia was probably reduced by half in the four years of Khmer Rouge rule;^{[citation needed]} it seems that there was an increased number of anti-Chinese events just prior to the Vietnamese invasion which brought an end to the Pol Pot regime.^{[citation needed]}