The Occupation of the Rhineland placed the region of Germany west of the Rhine river and four bridgeheads to its east under the control of the victorious Allies of World War I from 1 December 1918 until 30 June 1930. The occupation was imposed and regulated by articles in the Armistice of 11 November 1918, the Treaty of Versailles and the parallel agreement on the Rhineland occupation signed at the same time as the Versailles Treaty. The Rhineland was demilitarised, as was an area stretching fifty kilometres east of the Rhine, and put under the control of the Inter-Allied Rhineland High Commission, which was led by a French commissioner and had one member each from Belgium, Great Britain and the United States. The purpose of the occupation was to give France and Belgium security against any future German attack and serve as a guarantee for Germany's reparations obligations. After Germany fell behind on its payments in 1922, the occupation was expanded to include the industrial Ruhr valley from 1923 to 1925.

The Inter-Allied Rhineland High Commission was created by the Treaty of Versailles on 28 June 1919, to supervise the occupation of the Rhineland and "ensure, by any means, the security and satisfaction of all the needs of the Armies of Occupation". It came into being on 10 January 1920, when the treaty came into force. It was based in Coblenz.