Eleonore Charlotte of Saxe-Lauenburg-Franzhagen (German: Eleonore Charlotte von Sachsen-Lauenburg; born: 8 August 1646 in Marienfließ in Pomerania; died: 26 January 1709 in Franzhagen Castle, Schulendorf) was a duchess of Saxe-Lauenburg by birth and, by marriage, Duchess of Schleswig-Holstein-Sonderburg-Franzhagen, whose line and territorial legacy she co-founded.
After the death of her older sister Erdmuthe Sophie in 1689, Eleonore Charlotte became the heiress of Franzhagen with the corresponding Castle.
In 1667 Christian Adolph and his hereditary estates went bankrupt, and King Frederick III of Denmark as the liege lord retracted the fief.
After the death of her cousin Julius Francis, the last Duke of Saxe-Lauenburg, Eleanor Charlotte - like his daughters Anna Maria Franziska and Sibylle - unsuccessfully argued that she should inherit.
[1] The couple moved to Franzhagen Castle in the Duchy of Saxe-Lauenburg, which Eleonore Charlotte had inherited, thereby founding the Schleswig-Holstein-Sonderburg-Franzhagen line.