Arendt was born into a secular family of German Jews in Linden (present-day Hanover), the daughter of Martha (born Cohn) and Paul Arendt. She grew up in Königsberg (renamed Kaliningrad and annexed to the Soviet Union in 1946) and Berlin. At the University of Marburg, she studied philosophy with Martin Heidegger.
According to Hans Jonas, her only German-Jewish classmate, Arendt embarked on a long and stormy romantic relationship with Heidegger, for which she later was criticized because of Heidegger's support for the Nazi Party when he was rector at the University of Freiburg.
In the wake of one of their breakups, Arendt moved to Heidelberg, where she wrote her dissertation under the existentialist philosopher-psychologist Karl Jaspers on the concept of love in the thought of Saint Augustine. In 1929, in Berlin, she married Günther Stern, later known as Günther Anders. (They divorced in 1937.) The dissertation was published in 1929. Arendt was prevented from "habilitating"—a prerequisite for teaching in German universities—because she was Jewish. She researched anti-Semitism for some time before being arrested and briefly imprisoned by the Gestapo in 1933.
In 1933, Arendt left Germany for Czechoslovakia and then Geneva, where she worked for some time at the League of Nations before leaving for Paris, where she befriended the Marxist literary critic and philosopher, Walter Benjamin, her first husband's cousin. While in France, she worked to support and aid Jewish refugees. In 1937, she was stripped of her German citizenship. In 1940, she married the German poet and Marxist philosopher Heinrich Blücher, a former member of the Communist Party of Germany. Later that year, after the German military occupation of northern France, the Vichy regime began deportation of foreign Jews to concentration camps in the unoccupied south of France, and she was interned in Camp Gurs as an "enemy alien".
Like many others Arendt was able to leave Gurs after a few weeks and left France in 1941 with her husband and her mother via Portugal to the United States. They relied on visas illegally issued by the American diplomat Hiram Bingham, who aided roughly 2,500 Jewish refugees in this way. Varian Fry, another American humanitarian, paid for their travel and helped obtain the visas. Upon arriving in New York, Arendt became active in the German-Jewish community. From 1941–45, she wrote a column for the German-language Jewish newspaper, Aufbau. From 1944, she directed research for the Commission of European Jewish Cultural Reconstruction and traveled frequently to Germany in this capacity.
After World War II, she returned to Germany and worked for Youth Aliyah, a Zionist organization, which saved thousands of children from the Holocaust and settled them in the British Mandate of Palestine. She became a close friend of Karl Jaspers and his wife, developing a deep intellectual friendship with him. She began corresponding with American author Mary McCarthy around this time.
In 1950, Arendt became a naturalized citizen of the United States. She served as a visiting scholar at the University of California, Berkeley, Princeton University, and Northwestern University. In 1959, she was named the first female lecturer at Princeton. She also taught at the University of Chicago from 1963 to 1967, where she was a member of the Committee on Social Thought; The New School in Manhattan; Yale University, where she was a fellow; and, the Center for Advanced Studies at Wesleyan University (1961–62, 1962–63).
She was elected a fellow of the American Academy of Arts and Sciences in 1962 and a member of the American Academy of Arts and Letters in 1964.
Arendt was instrumental in the creation in 1974 of Structured Liberal Education (SLE) at Stanford University. She wrote a letter to the then president of Stanford University to persuade the university to enact Mark Mancall's vision of a residentially-based humanities program.
Arendt died in New York City on 4 December 1975, at age 69, of a heart attack. She was buried alongside her husband, Heinrich Blücher at Bard College in Annandale-on-Hudson, New York.