The Yugoslav coup d'état took place on 27 March 1941 in Belgrade, Kingdom of Yugoslavia, when the regency led by Prince Paul of Yugoslavia was overthrown and King Peter II fully assumed monarchical powers. The coup was planned and conducted by a group of pro-Western Serbian-nationalist Royal Yugoslav Air Force officers formally led by the Air Force commander, General Dušan Simović, who had been associated with several putsch plots from 1938 onwards. Brigadier General of Military Aviation Borivoje Mirković, Major Živan Knežević of the Yugoslav Royal Guards, and his brother Radoje Knežević were the main organisers in the overthrow of the government. In addition to Radoje Knežević, some other civilian leaders were probably aware of the takeover before it was launched and moved to support it once it occurred, but they were not among the organisers. Peter II himself was surprised by the coup, and heard of the declaration of his coming-of-age for the first time on the radio.

The Kingdom of Yugoslavia was a country in Southeast and Central Europe that existed from 1918 until 1941. From 1918 to 1929, it was officially called the Kingdom of Serbs, Croats, and Slovenes, but the term "Yugoslavia" was its colloquial name due to its origins. The official name of the state was changed to "Kingdom of Yugoslavia" by King Alexander I on 3 October 1929.