The Korean axe murder incident (Korean: ; Hanja: ,, lit.'Panmunjom axe murder incident') was the killing of two US Army officers, Captain Arthur Bonifas and First Lieutenant Mark Barrett, by North Korean soldiers on August 18, 1976, in the Joint Security Area (JSA) in the Korean Demilitarized Zone (DMZ). The US Army officers had been part of a work party cutting down a poplar tree in the JSA.

Three days later, American and South Korean forces launched Operation Paul Bunyan, an operation that cut down the tree with a show of force to intimidate North Korea into backing down, which occurred. North Korea then accepted responsibility for the earlier killings.

The incident is also known alternatively as the hatchet incident, the poplar tree incident, and the tree trimming incident.

The Korean Demilitarized Zone (한반도 비무장 지대 / 韓半島非武裝地帶; Hanbando Bimujang Jidae) is a strip of land running across the Korean Peninsula near the 38th parallel north. The demilitarized zone (DMZ) is a border barrier that divides the Korean Peninsula roughly in half. It was established to serve as a buffer zone between the countries of North Korea and South Korea under the provisions of the Korean Armistice Agreement in 1953, an agreement between North Korea, China, and the United Nations Command.

The DMZ is 250 kilometers (160 mi) long and about 4 kilometers (2.5 mi) wide. There have been various incidents in and around the DMZ, with military and civilian casualties on both sides. Within the DMZ is a meeting point between the two nations, where negotiations take place: the small Joint Security Area (JSA) near the western end of the zone.