Cambodia–United Kingdom relations refer to bilateral relations between Cambodia and the United Kingdom. They established diplomatic relations in 1953, following Cambodia's independence from France. The UK was the first country to condemn the human rights record in Cambodia in 1978. The British embassy was opened in Phnom Penh in 1953 until March 1975, a month before the Khmer Rouge-takeover. It was reopened in 1991 following the signing of the Paris Peace Accords.
The first British ambassador was posted to Phnom Penh in 1953 but the embassy of the United Kingdom was closed in 1975. The UK recognised the government of Democratic Kampuchea in 1976 however the embassy was not reopened. Britain was the first country to publicly condemn human rights record in Cambodia in 1978 and the British government withdrew its recognition of Democratic Kampuchea in 1979. In 1991, a British Mission was opened in Phnom Penh which became the British Embassy following the 1993 elections.
The UK contributes to Cambodia around £10m per year, mainly to promote democratic reform, human rights and good governance, health, education, urban poverty projects, the development of rural livelihoods, and to tackle the growing problems of paedophilia, people trafficking, forestry crime, and the spread of HIV.