Bibiana Beglau was born on July, 8, 1971 in Braunschweig, attended Waldorf school and completed acting training at the School for Music and Theatre in Hamburg. She received her first engagement in 1996 at the Schauspielhaus Düsseldorf, were she worked until 1998. Afterwards she appeared on stage in several productions of classic and modern plays at the Schauspielhaus Hamburg, the Kampnagel Hamburg, the Berlin Baracke, the Schauspielhaus Zurich, the Berlin Schaubühne and the Burgtheater in Vienna. She worked with filmmakers like Christoph Schlingensief (for example in "Hamlet", 2001/2002), Frank Castorf (among others in "Trauer muss Elektra tragen", 2003) and Falk Richter ("Drei Schwestern", 2007-2009, and others) and in 2008 she received the audience award as part of the company of the Schauspielhaus Zürich for their performance in "Macbeth". From 2009 to 2011 Beglau was a member of the ensemble at Hamburg's Thalia Theater, and in 2011 she moved to the Residenztheater in Munich. Since the 2019/20 season, she has been an ensemble member of the Burgtheater in Vienna.

Bibiana Breglau made her debut as a movie actress in 1994 in Matti Geschonneck's thriller "Der Mörder und sein Kind", which was produced for television, alongside Ulrich Tukur and Ulrich Matthes. Further leading- and supporting roles followed. She participated in television productions like "Gegen den Strom" (1997), "Der Briefbomber" (2000), "Nachtangst" (2004) or Dieter Wedel's two part series "Gier" (2010) as well as in a couple of "Tatort" episodes.

After appearances in the early short-films of Janek Rieke ("Frank", 1999) and Hans Weingartner ("Doppelpass", 2000) Beglau created a sensation right away in her first role in a feature film: In Volker Schlöndorff's entry at the Berlinale "Die Stille nach dem Schuß" ("The Legends of Rita", 2000) she plays (fictitious) RAF-terrorist Rita Vogt and together with Nadja Uhl she immediately received the Silver Bear as best actress for her outstanding performance. In the years to follow she had further much-noticed roles, like in the drama "Birthday" (2001), in which the character she portrays wants to commit suicide on her 30th birthday, in Schlöndorff"s highly acclaimed "Der neunte Tag" ("The Ninth Day", 2004), as the sister of a priest on "day parole" from a concentration camp and in the award-winning drama "Kammerflimmern" ("Off Beat", 2004) as an emergency doctor with the telling name "Dr. Tod" ("Dr Death"). For her emphatic portrayal of a mother who wants to protect her seven year old son, who has possibly become a murderer, from police in "Unter dem Eis" ("Under the Ice", 2005), Beglau received the Grimme Award. In the same year she played in "3 Grad kälter" ("3 Degrees Colder") a woman, whose life is thrown off the track by the reappearance of her boyfriend who was missing for years.

Despite such achievements she couldn"t be seen all too often on the big screen afterwards. In 2009, Breglau appeared in the psychological thriller "Was du nicht siehst" (2009) with Alice Dwyer, and together with Christian Berkel in the horror movie "Der letzte Angestellte" ("The Last Employee", 2010). She also was one of the leads in the award-winning drama "Und morgen Mittag bin ich tot" ("Zurich", 2013). On TV, she starred in the historical drama "Die Machtergreifung" (2012) and in the biopic "Helmut Schmidt - Lebensfragen" (2013).

For her performances in productions of "Die bitteren Tränen der Petra von Kant" und "Kasimir und Karoline" at the Residenztheater in Munich, Bibiana Beglau was awarded the 2012 Kurt-Meisel-Preis. In 2014, she was voted Actress of the Year by the trade magazine "Theater heute", and in 2015 she received the German Theater Award "Der Faust" for her role as Mephisto in Martin Kušej's production of "Faust".

She continued to star in numerous TV productions, including "Unter der Haut" (2015) and "Über Barbarossaplatz" (2016). In 2017, she was one of the leads in the theatrical release "1000 Arten, den Regen zu beschreiben" ("Different Kinds of Rain"). The subsequent film "Sieben Stunden" ("Seven Hours") was also dramatic material. The film is partly based on true events, but then fictionalizes the traumatic story of prison therapist Susanne Preusker (called Hanna Rautenberg in the film and played by Beglau), who was raped and tortured by a patient for hours in her office.   

After an appearance in the crime movie "Zorn" of the "Tatort" series (2019, directed by Andreas Herzog), she was then seen on the big screen in the same year in the youth film "Die drei !!!" ("The Three Exclamation Marks") as the mother of the young junior detective Kim.   

Also in 2019, Jan Bonny's "Jupp, watt hamwer jemaht?" with Beglau premiered at the Munich Film Festival. The project is a mixture of feature film and theater production that sees itself as a satire on the art world of the noughties in Germany. Again directed by Jan Bonny, she played the wife of the murder victim in her ninth participation in a crime thriller from the "Tatort" series, "Ich hab im Traum geweinet." The film was broadcast on German TV in February 2020. In September of the same year, she played the supporting role of a German lawyer in the Swiss-German co-production "Bis wir tot sind oder frei" ("Caged Birds"), which was screened publicly for the first time in the digital edition of the Hamburg Film Festival.  

In March 2021, filming began on Hanna Doose's second feature, "Wann kommst Du meine Wunden küssen," in which Beglau stars alongside Gina Henkel and Katharina Schröter as one of three women whose friendship has suffered deep rifts and who soon face existential questions when they meet.  

In addition to her work as an actress, Bibiana Beglau has repeatedly read and recorded audio productions, including the highly acclaimed radio play production of Emily Brontë's "Wuthering Heights" (2012) and Christa Wolf's "Kein Ort. Nowhere." In 2017, she was awarded the German Audiobook Prize for Best Performer for her reading of Thea Dorn's "Die Unglückseligen."