Marta Feuchtwanger, née Löffler, was born to a German Jewish family in Munich. She grew up to be an independent, dark-haired beauty interested in gymnastics and skiing. Her parents would not permit her to attend university or take voice studies as these were not considered proper activities for a well-brought-up young lady. But she read widely and taught herself French, English and Italian.
She met Lion Feuchtwanger, then a theater critic, when she was 18 and they became lovers. In 1912, she became pregnant and they married. The baby died and the couple spent months wandering through Europe. In 1930, her husband published his first novel, Success, which made him a target of the Nazi Party. The Feuchtwangers, along with many of their friends, fled to France after the Nazis rose to power in 1933, only to be interned there when France fell to Germany in World War II. Marta and her husband were imprisoned in separate camps until, with the help of some false identification papers and disguises provided by an American consul, they escaped. They hiked through the Pyrenees to Spain and managed to find their way to the USA. Their home in Pacific Palisades, California, became a gathering place for émigré intellectuals and artists such as Albert Einstein, Thomas Mann, Bertolt Brecht, Kurt Weill, Arnold Schoenberg, Charlie Chaplin, and Peter Lorre. She and her husband collected one of the most comprehensive private libraries on the West Coast. After her husband's death, she donated the 40,000 volumes to the University of Southern California.