Borders and other                     Border of Lithuania (1945 – present)
                     Border of Vilnius Region: Polish territory; claimed by Lithuania based on the Soviet–Lithuania Peace Treaty of 1920; occupied by the Soviet Union in September 1939
 Soviet military bases established in Lithuania according to the Soviet–Lithuania Mutual Assistance Treaty, signed on October 10, 1939

Klaipėda Region  Klaipėda Region: detached from the German Empire by the Treaty of Versailles; placed under administration of the Entente; taken by Lithuanians during the Klaipėda Revolt in January 1923; part of Nazi Germany after an ultimatum on March 20, 1939
Suwałki Region  Territory west of the Šešupė River: Lithuanian territory; requested by Nazi Germany in the German-Soviet Boundary and Friendship Treaty on September 28, 1939; occupied by the Soviet Union on June 15, 1940; Nazi Germany relinquished its claims for a compensation in the amount of $7.5 million on January 10, 1941
  "Suwałki Triangle": Polish territory, before 1795 Grand Duchy of Lithuania part of Polish–Lithuanian Commonwealth; claimed by Lithuania; occupied by Nazi Germany in September 1939
  Southern Suwałki Region: Polish territory, before 1795 Grand Duchy of Lithuania part of Polish–Lithuanian Commonwealth; claimed by Lithuania; occupied by the Soviet Union in September 1939
Vilnius Region

  Western Vilnius Region: transferred to Lithuania based on the Soviet–Lithuania Mutual Assistance Treaty, signed on October 10, 1939
  Western Vilnius Region: transferred to Lithuanian SSR on November 6, 1940
  Eastern Vilnius Region: by peace treaty of Moscow July 20, 1920, acknowledged by Russia to be "for all times" part of Lithuania
Eigenes Werk (own work) based on the original Image:Lithuania_territory_1939-1940.svg, made by Renata3
Furfur