The Klaipėda Revolt took place in January 1923 in the Klaipėda Region (also known as the Memel Territory or Memelland). The region, located north of the Neman River, was detached from East Prussia, German Empire by the Treaty of Versailles and became a mandate of the League of Nations. It was placed under provisional French administration until a more permanent solution could be worked out. Lithuania wanted to unite with the region (part of Lithuania Minor) due to its large Lithuanian-speaking population of Prussian Lithuanians and major port of Klaipėda (Memel) – the only viable access to the Baltic Sea for Lithuania. As the Conference of Ambassadors favoured leaving the region as a free city, similar to the Free City of Danzig, the Lithuanians organized and staged a revolt.
Presented as an uprising of the local population, the revolt met little resistance from either the German police or the French troops. The rebels established a pro-Lithuanian administration, which petitioned to unite with Lithuania, citing the right of self-determination. The League of Nations accepted the fait accompli and the Klaipėda Region was transferred as an autonomous territory to the Republic of Lithuania on February 17, 1923. After prolonged negotiations, a formal international agreement, the Klaipėda Convention, was signed in May 1924. The convention formally acknowledged Lithuania's sovereignty in the region and outlined its extensive legislative, judicial, administrative, and financial autonomy. The region remained part of Lithuania until March 1939 when it was transferred to Nazi Germany after a German ultimatum.
The German–Lithuanian border had been stable since the Treaty of Melno in 1422. However, northern East Prussia had a significant Lithuanian-speaking population of Prussian Lithuanians or Lietuvninkai and was known as Lithuania Minor. The Klaipėda Region covered , which included the Curonian Lagoon of approximately . According to the Prussian Census of 1910, the city of Memel numbered 21,419 inhabitants, of whom 92% were German and 8% were Lithuanian, while the countryside was inhabited by a Lithuanian majority of 66%.