Mario Adorf was born on September 8, 1930, in Zurich, Switzerland, to an Italian father and a German mother. He grew up with his single mother in the Eifel region of Germany. After finishing school in 1950, he enrolled at the University of Mainz, where he studied a range of subjects, including German literature, philosophy, and theater studies. During this time, he was active both in a student boxing club and on a student stage. After a few semesters, he transferred to the University of Zurich, where he worked as an extra and assistant director at the Schauspielhaus theater. In 1953, Adorf gave up his studies for good and began training as an actor at the Otto Falckenberg School in Munich. From 1955 to 1962, he performed at the Munich Kammerspiele, appearing in classics such as "A Streetcar Named Desire" and "Othello."

Even while still in acting school, Adorf landed his first film role in 1954 in Paul May’s war drama "08/15." His breakthrough came three years later with the lead role in Robert Siodmak’s psychological drama "Nachts wenn der Teufel kam" ("The Devil Strikes At Night"), in which he gave a haunting performance as a mentally unstable murderer. The role won him the German Film Award as "Best Young Actor," but it also typecast him for years as a villain and tough outlaw. He appeared in roles such as in Georg Tressler’s "Das Totenschiff" ("Ship of the Dead," 1959), as a young gang leader in Gerd Oswald’s "Am Tag, als der Regen kam" ("The Day It Rained," 1959), and as the murderous bandit Santer in Harald Reinl’s "Winnetou I" (1963).

In the early 1960s, Adorf moved to Italy, seeking opportunities in international cinema at a time when German film production was in decline. By the mid-1970s, alongside his German work, he had appeared in countless international films, often cast as a shady or rough-edged character. His reputation allowed him to collaborate with some of the world’s most renowned directors, including Sam Peckinpah ("Major Dundee," 1964), Sergio Corbucci ("The Specialists," 1969), Billy Wilder ("Fedora," 1978), John Frankenheimer ("The Holcroft Covenant," 1985), and Claude Chabrol ("Quite Days in Vichy," 1990). Although he often played supporting roles, Adorf was one of the few German-speaking actors of his time to gain international recognition.

In the 1970s, directors of the New German Cinema discovered him, leading to some of the most acclaimed and popular performances of his career: as the gangster Die Ratte in Roland Klick’s genre film "Deadlock," as a hard-bitten policeman in Volker Schlöndorff’s "Die verlorene Ehre der Katharina Blum" ("The Lost Honor of Katharina Blum," 1975), as a blind criminal in Nikos Perakis’ tragicomedy "Bomber und Paganini" ("Bomber & Paganini," 1976), as a corrupt businessman in Rainer Werner Fassbinder’s "Lola" (1981), and as a petty opportunist and Nazi follower in Schlöndorff’s Oscar-winning "Die Blechtrommel" ("The Tin Drum," 1979). His popularity was also reflected in major awards, such as the "Bambi" in 1978 as "Most Popular Actor of the Year" and the German Film Award in Silver in 1982 for his role in "Lola."

Adorf was equally successful on television. His portrayal of a brutal father in Tom Toelle’s acclaimed "Via Mala" (1985) remains unforgettable, as does his performance as a nouveau-riche industrialist in an episode of Helmut Dietl’s mini-series "Kir Royal" (1986). He also enjoyed a particularly fruitful partnership with TV director Dieter Wedel, starring in hugely popular multi-part series such as "Der große Bellheim" (1993) and "Der Schattenmann" (1996).

In 1992, Adorf won the German Film Award in Gold for his role as a warm-hearted Italian restaurant owner in "Pizza Colonia." Four years later, he played another restaurateur – this time a fashionable Munich society figure – in Helmut Dietl’s satire "Rossini oder die mörderische Frage, wer mit wem schlief" ("Rossini").

Among Adorf’s most important later films are "Epsteins Nacht" ("Epstein's Night," 2001), in which he played a former concentration camp inmate who believes he recognizes his former tormentor in the local priest, as well as the family films "Es ist ein Elch entsprungen" ("A Christmoose Carol," 2005) and "Die Rote Zora" ("Red Zora," 2008). These roles once again showed the impressive range of an actor who had long since outgrown the villain roles that marked the beginning of his career. 

Also after his 80th birthday, Adorf maintained his high-profile and industrious schedule as an actor. He starred as a marzipan manufacturer struggling to save his empire in the made-for-TV movie "Der letzte Patriach" (2010). He then delivered a memorable performance as a Czech war criminal who is confronted by the relatives of his victims after the end of WWII in Nikolaus Leytner's "Die lange Welle hinterm Kiel".

In 2012, Adorf returned to the big screen with "Die Libelle und das Nashorn" ("The Rhino and the Dragonfly"): He plays an aging, narcissistic movie star, who spends an eventful night in a luxury hotel with an upcoming female author, whom he initially dislikes.

He then excelled in Urs Egger's made-for-TV drama "Krokodil" (2013) as a successful writer whose secluded life is turned upside down by a young woman and her little son. In Anna Justice's two-part TV production "Pinocchio" (2013) he featured as the warm-hearted and slightly melancholy woodcarver Gepetto, a distinguished role for Adorf. At the Munich International Film Festival 2013, Lola Randl's "Die Erfindung der Liebe" ("The Invention of Love") premiered. The film that took a long time to finish after the female lead Maria Kwiatkowsky had died unexpectedly in 2011 features Adorf in a minor role as an elegant aristocrat.

He starred in a strong role in "Der letzte Mentsch" ("The Last Mentsch", 2014) as a concentration camp survivor who had started a new life as a "German" after the war and now has to prove his Jewish ancestry in order to be buried on a Jewish cemetery. Shortly after, Adorf featured again in a film widely praised by the critics – Jan Georg Schütte's largely improvised ensemble comedy "Altersglühen" (2014, TV) – where he personified a widower who had promised is dying wife to find a new partner.

After featuring as the main character's father in Dani Levy's comedy "Der Liebling des Himmels" (2015, TV), Mario Adorf returned to where his career had started: The made-for-TV movie "Winnetou" (2016) features him as the murderous bandit Santer once again, just like the original from 1963.

He had a smaller but important role as the strict father of the title character in the comedy "Schubert in Love – Vater werden ist (nicht) schwer" (2016). In the low-budget production "Real Fight" (2017) he played the part of an oligarch, in the much-praised TV comedy "Einmal Sohn, immer Sohn" (2018) with Christiane Hörbiger he made a fine guest appearance as a star architect.  

In 2018, the city of Worms and the Nibelungenfestspiele Worms awarded the Mario-Adorf Prize, named after Adorf, for the first time. The prize is awarded to participants of the Nibelungenfestspiele. Adorf himself, who was one of the initiators of the festival in 2002 and has been a member of the board of trustees since, is also a member of the jury.   

In 2018 he starred in the title role of the ZDF documentary drama "Karl Marx - Der deutsche Prophet". He played his signature role in the two-parter "Alle für die Mafia" (DE/AT) as a Mafioso, who is banished from Sicily to a South Tyrolean village.   

In 2019 Mario Adorf himself was the subject of a film: In "Es hätte schlimmer kommen können - Mario Adorf" ("It Could Have Been Worse – Mario Adorf") director Dominik Wessely paints a multi-layered portrait of the legendary actor.