Eleonore Wilhelmine of Anhalt-Köthen (7 May 1696 in Köthen – 30 August 1726 in Weimar) was a princess of Anhalt-Köthen by births and by marriage successively Princess of Saxe-Merseburg and Duchess of Saxe-Weimar.

Eleonore Wilhelmine was the eldest daughter of Prince Emmanuel Lebrecht of Anhalt-Köthen (1671-1704) from his marriage with Gisela Agnes of Rath, Countess of Nienburg (1669-1740).

On 24 January 1716 in Nienburg, Saxony-Anhalt, Eleonore Wilhelmine married for the second time, to Duke Ernest Augustus I of Saxe-Weimar and Saxe-Eisenach (1688-1748).

[1] Eleonore Wilhelmine later became the godmother of Bach's son Leopold Augustus.

From her second marriage, to Ernest Augustus I of Saxe-Weimar, Eleonore Wilhelmine had the following children: