The Lithuanian Civil War of 1381–1384 is the first struggle for power between the cousins Jogaila, Grand Duke of Lithuania and later King of Poland, and Vytautas the Great.

It begins after Jogaila signs the Treaty of Dovydiškės with the Teutonic Knights, which is aimed against his uncle Kęstutis, father of Vytautas.

Kęstutis briefly seizes power in the Grand Duchy, but is betrayed by adherents of Jogaila primarily from Vilnius.

During negotiations for a truce Kęstutis and Vytautas are arrested and transported to the Kreva Castle.

Kęstutis dies there a week later but Vytautas manages to escape, then seeks an alliance with the Teutonic Knights.

Subsequently their joint forces raid Lithuanian lands.

Eventually the cousins are reconciled as Jogaila needs internal stability in anticipation of negotiations with the Grand Duchy of Moscow and the Kingdom of Poland regarding the possible Christianization of Lithuania.

The war does not settle the power struggle; it continues during the next Lithuanian Civil War (1389–1392) which is resolved by the signing of the Ostrów Agreement.

After more than ten years of struggle, Vytautas finally becomes the Grand Duke of Lithuania and will rule the country for thirty-eight years.