The Klaipėda Region (Lithuanian: Klaipėdos kraštas) or Memel Territory (German: Memelland or Memelgebiet) was defined by the Treaty of Versailles in 1920 when it was put under the administration of the Council of Ambassadors. The Memel Territory, together with Saar and Danzig, was to remain under the control of the League of Nations until a future day when the people of these regions would be allowed to vote on whether the land would return to Germany or not.

The original Scalovian and Curonian territory was conquered around 1252 by the Teutonic Knights, who constructed Memelburg ("Memel Castle") and the city of Memel (now usually known by its Lithuanian name Klaipėda). In 1422, a border was drawn up between Prussia and Lithuania under the Treaty of Melno, and this border existed up to 1918.

The then predominantly ethnic German (other ethnic groups, Prussian Lithuanians and Memellanders constituted the other ethnic groups) Memel Territory, situated between the river and the town of that name, was occupied by Lithuania in the "Klaipėda Revolt" of 1923. It was annexed by Nazi Germany in March, 1939 and immediately reintegrated into East Prussia, just half a year before the outbreak of the Second World War. In the final stages of the war in 1945 it was occupied by Soviet forces, and was formally annexed by the Soviet Union in 1946, cleared of its native German population, and made a part of the Lithuanian SSR in 1948. Since the collapse of the Soviet Union in 1990, it has been part of the Republic of Lithuania and contained within Klaipėda and Tauragė Counties. The border, that was established by the Treaty of Versailles along the river, remains in effect as the current international boundary between Lithuania and the Kaliningrad Oblast of Russia.

Klaipėda (pronounced [ˈklaɪpeːda] ( listen); German: Memel) is a city in Lithuania situated at the mouth of the Danė River where it flows into the Baltic Sea. It is the third largest city in Lithuania and the capital of Klaipėda County.

The city has a complex recorded history, partially due to the combined regional importance of the Port of Klaipėda, a usually ice-free port on the Baltic Sea, and the Akmena - Danė River. It has been controlled by the Teutonic Knights, the Duchy of Prussia, the Kingdom of Prussia, the German Empire, the Entente States immediately after World War I, Lithuania as a result of the 1923 Klaipėda Revolt, and the Third Reich following the 1939 German ultimatum to Lithuania. The city was incorporated into Lithuania during its tenure as a Soviet Socialist Republic and has remained within Lithuania following its re-establishment as an independent state.

The population shrank from 207,100 in 1992 to 177,823 in 2011. Popular seaside resorts found close to Klaipėda are Nida to the south on the Curonian Spit, and Palanga to the north.