(Anna Charlotte) Dorothea von Medem (3 February 1761 – 20 August 1821) was born a Gräfin (Countess) of the noble German Baltic Medem family and later became Duchess of Courland (a Baltic region).
Popularly known as Dorothea of Courland after her marriage to Peter von Biron, the last Duke of Courland, she hosted an aristocratic salon in Berlin and performed various diplomatic duties on behalf of her estranged husband.