Maria Gräfin von Maltzan was born near Breslau in 1909. She studied sciences and gained a doctorate in 1933. That same year, she joined a resistance circle formed around the Munich Jesuit priest Friedrich Muckermann.
In 1935 she moved to Berlin, where she met the Jewish writer Hans Hirschel in 1939. The two became a couple. From 1942 Hirschel lived in hiding with Maltzan. She was denounced in 1943 and the Gestapo searched her home for hours. At the last minute, Hirschel had hidden under a prepared folding couch, and remained undiscovered.
Maltzan later took in other persecuted Jews. She ran an animal shelter and worked in slaughterhouses, which meant she could obtain food and medication for people in hiding. Along with other helpers from the Swedish Victoria congregation in Berlin-Wilmersdorf, Maltzan helped Jews to escape to Sweden.
Maria von Maltzan experienced the end of the war with Hans Hirschel in Berlin. She received several awards for her acts of courage. In 1987 she was honored as Righteous Among the Nations and in 1999 a memorial plaque was unveiled outside her former home.