Hanna Ralph was born in Bad Kissingen, Germany, she made her stage debut in 1913 at the Schauspielhaus in Frankfurt.

[2] Hanna Ralph made her screen debut in the 1917 Ludwig Beck-directed short Die entschleierte Maja, opposite actor Walter Janssen and the following year had a starring role in director Georg Jacoby's Keimendes Leben, Teil 1, opposite Emil Jannings.

In 1924 she appeared in the Herbert Wilcox-directed romantic drama Decameron Nights opposite American stage and screen actor Lionel Barrymore, and in Fritz Lang's silent fantasy film Die Nibelungen, based on the epic poem Nibelungenlied, as Brunhild.

Murnau-directed, Universum Film AG (UFA) distributed Faust – Eine deutsche Volkssage opposite Gösta Ekman, Camilla Horn and ex-husband Emil Jannings.

After the war's end, she briefly returned to film in the early 1950s; appearing in small roles in director Wolfgang Liebeneiner's 1951 crime drama The Blue Star of the South and Harald Reinl's 1952 drama Behind Monastery Walls before retiring from acting altogether.