Countess Elisabeth of Nassau (Elisabeth Flandrika) (Middelburg, 26 April 1577 – Sedan, 3 September 1642) was the second daughter of prince William of Orange and his third spouse Charlotte of Bourbon. She was Duchess of Bouillon by marriage.
After her father was murdered in 1584, there was a shortage of money for Elisabeth, her siblings and her stepmother Louise de Coligny. In 1594 Louise took Elisabeth with her to France, where they met with several Protestant nobles. One of them, Henri de La Tour d'Auvergne, of the Duchy of Bouillon and the Principality of Sedan, sent her a proposal of marriage that she accepted. The couple had nine children.
Henri tried to keep his Duchy Sedan Protestant, but had to deal with hostility emanating from his catholic French neighbors.
During his absences Louise acted as regent, and after his death in 1623 she became regent for their son Frédéric Maurice de la Marck. She kept in close contact with her stepmother and five sisters, two of whom also acted as regents at some point.