The Duchy of Saxe-Lauenburgball was a duchy in the extreme southeast region of Schleswig-Holsteinball.
Duchy of Saxe-Lauenburgball was partitioned from Duchy of Saxonyball in 1296. In 1303 he was partitioned to Duchy of Saxe-Mölln-Begedorfball and Duchy of Saxe-Ratzeburgball in 1401 He became indipendent again. From 1689 to 1705 he had a personal union with Principality of Lüneburgball and from 1705 to 1803 with Electorate of Hanoverball.He was dissolved in 1803 during the Napoleonic Wars. In 1814 he re-became indipendent and had a personal union with Denmarkball to 1864 and from 1865 to 1876 was in a personal union with Kingdom of Prussiaball and 1876 he merged into him.