The Khmer Republic was a Cambodian state under the United States-backed military dictatorship of Marshal Lon Nol from 1970 to 1975. Its establishment was formally declared on 9 October 1970, following the 18 March 1970 coup d'état which saw the overthrow of Norodom Sihanouk's government and the abolishment of the Cambodian monarchy.

Cambodia, officially the Kingdom of Cambodia, is a country in Southeast Asia on the Indochinese Peninsula, spanning an area of 181,035 square kilometres, bordered by Thailand to the northwest, Laos to the north, Vietnam to the east, and the Gulf of Thailand to the southwest. The capital and most populous city is Phnom Penh.