Miep Gies was born into a working class family in Vienna on February 15, 1909. Austria suffered from extreme food scarcity after World War I, and in the fall of 1920 a Dutch workers' association began an initiative that sent Austrian working class children to the Netherlands to regain their strength. Gies was transported from Vienna to Leidin in December 1920 with other Viennese children. In 1922, she moved with her foster parents, Mr. and Mrs. Nieuwenburg, to Amsterdam. Miep finished school at the age of 18, and found a job as office assistant at a textile company. At the textile company, she met Jan Gies, who was later to become her husband. In 1933, after being laid off, Miep met Otto Frank when she applied for the post of temporary secretary in his company, Opekta. Otto Frank was the director of the Nederlandsche Opekta company, which specialized in trading a substance used in the household production of jam.

Although Miep had been living in the Netherlands since December of 1920, she had always kept her Austrian nationality. Since Austria no longer existed after its annexation by Nazi Germany in 1938, Miep tried to obtain Dutch nationality in 1939 through a letter to Queen Wilhemina. In 1941, Miep was summoned to the German consulate. After handing over her Austrian passport, she was asked whether it was true that she had refused to join a Nazi girls' association. When she confirmed that this was true, the German entered a big black X next to the expiry date and returned her passport with the words: “Your passport has been invalidated. You must return to Vienna within three months. Unless you marry a Dutch man.” Miep and Jan Gies married on July 16, 1941.

In July 1942, Miep took on the responsibility of caring for the Frank and Van Pels family while they hid from the Nazis. The families hid in a secret upstairs room in the company's office building on Amsterdam's Prinsengracht. On the morning of August 4, 1944, the Grüne Polizei was tipped off by an informant and the office building was searched. They arrested the Frank and Van Pels family, as well as Victor Kugler and Johannes Kleiman. A few days later, Miep unsuccessfully tried to bribe the Austrian Nazi officer to release them. After the war, Otto Frank lived with Miep and Jan from 1945 until 1953. Miep had saved Anne’s diaries but had never read them. She returned the diaries to Otto and assisted in the translation and publication of the diaries. In 1994, Miep Gies was awarded the Order of Merit of the Federal Republic of Germany; in 1995, she received the Yad Vashem medal, and in 1997, she was knighted by Queen Beatrix of the Netherlands. Gies died on January 11, 2010 at the age of 101.