Ellen Marx (born Ellen Pinkus: 24 March 1921 – 11 September 2008) was a human rights activist.
She was born in Germany and emigrated to Argentina, arriving in May 1939: she never saw her parents again.
Her own youngest daughter disappeared when aged 28 in August 1976.
After that Ellen Marx became a prominent member of the German-Jewish community in Buenos Aires and a leader in the German originating group within the Mothers of the Plaza de Mayo movement.