Elisabeth Henriëtte of Hesse-Kassel (or Hesse-Cassel), Erbprinzessin of Brandenburg, Kurfürstin of Prussia (18 November 1661, Kassel - 7 July 1683 Cölln/Spree) was the daughter of William VI, Landgrave of Hesse-Kassel and Hedwig Sophie of Brandenburg (?-1683), a sister of Elector Frederick William of Brandenburg.
Landgräfin Hedwig Sophie promoted Elisabeth's marriage with Frederick I of Prussia, her cousin, on family grounds. However, the plans were scotched by other plans for Frederick to marry a sister of Holy Roman Emperor Leopold I, but they eventually came to fruition.
In April 1678 Hedwig Sophie and Elisabeth travelled to Berlin, but Elisabeth had to wait a year in the Stadtschloss, Berlin for her marriage, whilst Frederick was away signing the Treaty of Nijmegen. The marriage, however, turned out to be a love match - the young couple lived in Schloss Köpenick and had one child, a daughter called Louise Dorothea (1680- 1705). However, Elisabeth died at 21 after only 4 years of marriage and was buried in the Berliner Dom.