The Cambodia–Thailand border is the international border between Cambodia and Thailand. The border is 817 km (508 mi) in length and runs from the tripoint with Laos in the north-east to the Gulf of Thailand in the south.

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.