Barbara Auer, born February 1, 1959, in Konstanz, grew up as the eldest of four children in a staunchly Catholic home. After finishing school, Auer went to Hamburg and enrolled at Hochschule für Musik und Darstellende Kunst. In 1981, she made her stage debut at Stadttheater Mainz, went to Städtische Bühnen Osnabrück in 1983 and was a cast member at Schauspielhaus Wuppertal from 1986 to 1988. Furthermore, Auer made her movie debut in Alexander Kluge's 1982 film "Die Macht der Gefühle" ("The Power of Emotion"). In 1988, Auer won the Goldene Kamera for her portrayal of GDR crane operator Jessica in Vivian Naefe's TV movie "Der Boss aus dem Westen". Like in this film, Auer has often been seen in parts of down-to-earth, yet modern and self-confident women.

In 1993, Auer won the German film prize in Gold, for "Meine Tochter gehört mir" ("My Daughter Belongs to Me"), again directed by Vivian Naefe. Furthermore, Auer starred in leading roles in Sherry Horman's "Frauen sind was wunderbares" (1994) und in Frank Beyer's TV movie "Nikolaikirche" (1995). In 2001, Auer was again nominated for the German film prize for her performance in Christian Petzold's "Die innere Sicherheit" ("The State I Am In"). In this film, Auer played a former terrorist who is leading an underground existence together with her husband and her daughter. They have to hide from the police so that her daughter cannot lead a normal teenager's life.

In the following years, Auer starred for instance in Margarethe von Trotta's film "Ich bin die Andere" ("I Am the Other Woman," 2006). She also played leading roles in several TV dramas such as Thorsten Näter's "Einfache Leute" (2006). In 2007, Barbara Auer was again nominated for the German film prize as "best supporting actress" for her performance in "Der Liebeswunsch" ("Impossibly Yours"), an adaptation of the novel by Dieter Wellershoff directed by Torsten C. Fischer. Since 2006, Barbara Auer has starred alongside Armin Rohde as Chief Inspector Lisa Brenner in ZDF's crime series "Nachtschicht."  

On the big screen, she appeared in Hermine Huntgeburth's literary adaptation "Effi Briest" (2009) as the vain housekeeper of Baron von Instetten (Sebastian Koch). She also reunited with Sebastian Koch in the drama "In jeder Sekunde" ("At Any Second," 2008), this time playing his wife. The film, about a couple struggling with different ways of coping with their daughter's hereditary illness, won the Bavarian Film Award in 2009. Auer had smaller roles in Hans-Christoph Blumenberg's "Warten auf Angelina" ("Waiting for Angelina," 2008) and in "Das Wochenende" ("The Weekend," 2012), alongside Katja Riemann and Sebastian Koch, playing the sister of a prematurely released Red Army Faction member.

She then focused mainly on television for several years. In Matti Geschonneck's acclaimed and award-winning TV film "Das Ende einer Nacht" (2012), which deals with marital rape, Auer played the presiding judge—convinced of the defendant's guilt but challenged by a fiercely determined defense attorney (Ina Weisse). For their performances, both Auer and Weisse were honored with the Grimme Award, the German Television Award, and the Günter-Rohrbach Film Prize in 2012.

Another high-profile TV film was "Grzimek" (2014/15, dir. Roland Suso Richter), which traced both the professional milestones of the renowned zoologist and conservationist (Ulrich Tukur) and his unusual private life. Auer appeared as his wife Hilde, who supports her husband's work while struggling with his numerous affairs.

In the following years, Auer worked again with Christian Petzold in two "Polizeiruf 110" TV films: "Kreise" (2015) and "Wölfe" (2016), playing Hamburg detective Constanze Hermann, who assists Munich commissioner von Meuffels (Matthias Brandt) in their investigations. In the TV film "Landgericht" (2017), adapted from Ursula Krechel's award-winning novel, she starred alongside Johanna Wokalek and Ronald Zehrfeld as the secretary and confidante of a Jewish judge returning to postwar Germany. 

Her big screen appearances included Piotr Lewandowski's much-noticed Berlinale debut "Jonathan" (2016). In 2017, the TV drama "Krieg" by Rick Ostermann premiered at the Venice Film Festival as one of the few German productions, with Auer and Ulrich Matthes playing a couple whose son dies during an overseas military deployment. That same year, she reunited with Petzold for his free adaptation of Anna Seghers' novel "Transit," appearing in a supporting role.

Auer continued to work steadily in film and television: she starred in Sandra Nettelbeck's social portrait "Was uns nicht umbringt" ("What Doesn't Kill Us," 2018) and had a supporting role in Alain Gsponer's "Wolke unterm Dach" (2020). She also appeared in acclaimed TV productions such as the miniseries "Preis der Freiheit" ("Berlin Wall"/"The Wall," 2020), for which she won the German Television Award for Best Actress, as well as in the love-triangle drama "Sugarlove" (2021) and the thriller "Ewig Dein" (DE/AT 2023). 

She returned to cinemas in 2025 with a leading role in Christian Petzold's relationship and family drama "Miroirs No. 3," which premiered at the Cannes Film Festival and was released in German theaters in the fall of 2025.