The Concert of Europe, also known as the Congress System or the Vienna System after the Congress of Vienna, is a system of dispute resolution adopted by the major conservative powers of Europe to maintain their power, oppose revolutionary movements, weaken the forces of nationalism, and uphold the balance of power.

Historians date its operation from the end of the Napoleonic Wars (1815) to the late 1840s, although some see it playing a role until the Crimean War (1853–1856).