As the daughter of an uninvolved 22-year old single mother, she was raised by her maternal grandparents in Wuppertal, whom she says were outspoken anti-nazis. During World War II she evacuated to Bavaria, only returning to the Ruhr in 1950. After studying in France, Schwarzer began a trainee journalism job in Düsseldorf in 1966. In 1969 she started working as a Journalist.

From 1970 to 1974 she worked as a freelancer for different media in Paris. At the same time she studied psychology and sociology, amongst others lectured by Michel Foucault. Schwarzer met Jean-Paul Sartre and Daniel Cohn-Bendit. She was one of the founders of the Feminist Movement in Paris (Mouvement de Liberation des femmes, MLF) and also spread their ideas to Germany. In April 1971, Schwarzer joined Simone de Beauvoir, Catherine Deneuve, and 340 frenchwomen, in publicly announcing that they had each had illegal abortions in a successful campaign to legalize abortion in France.

In June 1971, Schwarzer did the same with 374 German women, including Romy Schneider, in a successful campaign to legalize abortion in Germany. She called her project Frauen gegen den § 218 ("Women against Section 218", which was the section of the German Penal Code that made abortion illegal). In autumn 1971 she released her first book of the same title. The West German legalization law was struck down by the German Constitutional Court abortion decision, 1975.

One of her best known books is Der kleine Unterschied und seine großen Folgen (The little difference and its huge consequences), which was released in 1975 and made her famous beyond the borders of Germany. It was translated into eleven languages. Since its release, Schwarzer has become Germany's most high-profile, but also most controversial contemporary feminist. She is a second-wave feminist representing concepts of feminist equality.

One of her goals was the realization of economic self-sufficiency for women. She argued against the law which required married women to obtain permission from their husbands before beginning paid work outside the home. This provision was removed in 1976.

In January 1977 the first issue of her journal EMMA was published. The next years she concentrated on the work for her journal, serving as chief Editor and publisher.

In the 1980s, Schwarzer set up a bank account at the Zürich-based private bank Lienhardt & Partner, to keep her assets hidden from German tax authorities. During the following years, Schwarzer transferred earnings gained from book-sellings and public presentations to this Swiss bank account, thus avoiding taxation in Germany. Including interest and compound interest, her illegal assets piled up to an amount of 4 Million Euros.

With her PorNo campaign, started in 1987, she advocated the banning of pornography in Germany, arguing that pornography violates the dignity of women, constitutes a form of medial violence against them, and contributes to misogyny and physical violence against women. The ongoing campaign has not met with much success.

From 1992 to 1993 she was host of the TV show Zeil um Zehn on German TV channel Hessischer Rundfunk. With her frequent appearances in German TV talk shows she has become an institution on German television in all matters related to feminism.

When her journal EMMA changed to bimonthly release in 1993, she continued to write an increasing number of books, among them one about Petra Kelly and Gert Bastian, called Eine tödliche Liebe (Deadly Love), and biographies of Romy Schneider and Marion Dönhoff. In total, she has released 16 books as a Writer, and 15 as publisher.

She campaigned against the law of 2002 that fully legalized brothels. She views prostitution as violence against women and favors laws like those in Sweden, where the sale of sexual services is legal but their purchase is not. (See also: Prostitution in Germany.)

In May 2014, German tax authorities and Criminal prosecutors raided a number of real estates owned by Schwarzer. At the same time, judge-issued search warrants on several of Schwarzer's banking accounts were executed. It turned out that Schwarzer's initial self-display submitted to German tax authorities was incorrect and she had in fact never covered the whole amount of her unpaid taxes. In such cases, self-displays do not have any exculpatory effect under German tax law. Consequently, in July 2016 Schwarzer was fined for tax fraud with a penalty at a six-digit range by the local court (Amtsgericht) of Cologne.

In July 2016 Schwarzer was convicted of tax fraud by the Amtsgericht Cologne; in the course of the case, which began in 2013, it was revealed that, since the 1980s, she had failed to pay taxes on approximately 4 million Euros that she had accumulated in a Swiss bank account.