The siege of the International Legations occurred in 1900 in Peking, the capital of the Qing Empire, during the Boxer Rebellion and led to the deaths of approximately 2500 Chinese people by western soldiers. Threatened by the Boxers—an anti-Christian, anti-foreign peasant movement—900 soldiers, sailors, marines, and civilians, largely from Europe, Japan, and the United States, and about 2,800 Chinese Christians took refuge in the Peking Legation Quarter. The Qing government took the side of the Boxers after the Eight-Nation Alliance invaded Tianjin at the Battle of the Taku Forts (1900), without a formal declaration of war. The foreigners and Chinese Christians in the Legation Quarter survived a 55-day siege by the Qing Army and Boxers. The siege was broken by an international military force, which marched from the coast of China, defeated the Qing Army, and occupied Peking.

The Boxer Rebellion, also known as the Boxer Uprising or the Boxer Insurrection, was an anti-foreign, anti-imperialist, and anti-Christian uprising in North China between 1899 and 1901, towards the end of the Qing dynasty, by the Society of Righteous and Harmonious Fists, known as the "Boxers" in English due to many of its members having practised Chinese martial arts, which at the time were referred to as "Chinese boxing". It was defeated by the Eight-Nation Alliance of foreign powers.