Born in Sicily, she spent most of her youth in Turin. She published her first story, I Bambini, in 1933 in the magazine Solaria. In 1938, she married Leone Ginzburg, and used the name Natalia Ginzburg (occasionally spelled "Ginzberg") on most subsequent publications. Her first novel, however, was published under the pseudonym Alessandra Tornimparte in 1942, during Fascist Italy's most anti-semitic period.

Ginzburg's father, Giuseppe Levi, a renowned Italian histologist, was born of a Jewish family. Her mother, Livia Tanzi, was Catholic. She was raised as an atheist. Although Ginzburg was able to live relatively free of harassment during World War II, her husband was forced to spend much of this period in a village in Abruzzo. Opponents of the Fascist regime, she and her husband secretly went to Rome and edited an anti-Fascist newspaper, until Leone Ginzburg was arrested and murdered in jail in 1944.

Ginzburg spent much of the 1940s working for the publisher Einaudi in Turin; her second novel was published in 1947. In 1950, she married Gabriele Baldini, a scholar of English literature. This was the beginning of the most prolific period of Ginzburg's literary career, during which she published most of the works for which she is best known. Her second husband died in 1969.

She played the role Mary of Bethany in Pasolini's The Gospel According to St. Matthew in 1964.

Natalia Ginzburg was politically involved throughout her life as an activist and polemicist. Like many prominent anti-Fascists, for a time she belonged to the Italian Communist Party. She was elected to the Italian Parliament as an Independent in 1983.

Natalia and Leone Ginzburg were the parents of the distinguished historian, Carlo Ginzburg.