Wieman was born in Osnabrück, the only son of Carl Philipp Anton Wieman and his wife Louise. Raised in Osnabrück, Wiesbaden and Berlin, where he studied four terms of philosophy, history of art and languages, Wieman wanted to actually become an airplane technical designer and flier. He started his acting career on the stage in Berlin under the direction of Max Reinhardt at the Deutsches Theater. In the early 1920s, he was a member of the Holtorf-Truppe, a stock theater group that included future director Veit Harlan. His fellow stage actors included his future wife, Erika Meingast, Marlene Dietrich, Dora Gerson and Max Schreck (the vampire in Nosferatu). Later he began working in silent and sound films; he landed supporting roles in Assassination, Queen Louise and Land Without Women. In 1930, along with Leni Riefenstahl, he appeared in Storm over Mont Blanc, and in 1932 he played the lead in Riefenstahl's The Blue Light.
At the height of his film career, during the decade of the 1930s, Wieman acted in such productions as Man Without a Name, L'Atlantide, The Countess of Monte-Christo, Fräulein Hoffmanns Erzählungen, Der Schimmelreiter, Viktoria, Patriots, and Togger.
In 1936 Wieman produced the Frankenburger Würfelspiel of the Nazi playwright Eberhard Wolfgang Möller in association with the 1936 Summer Olympics and the inauguration of the Dietrich-Eckart-Bühne, and also played the Black Knight.
He also had an international success with his appearance in The Eternal Mask. The movie was awarded with the American National Board of Review Award for Best Foreign Film in the United States in 1937 (National Board of Review Awards 1937). The film was also nominated for an award at the Venice Film Festival. Also in 1937, Wieman was made Staatsschauspieler, an honorary title bestowed by the German government and the highest honour attainable by an actor in Germany.
Wieman's life and work under the Nazi regime is a complex subject that can't be fairly or properly dealt with in a few sentences. Detailed information can be read (in German) at this excellent web site: Biographie des Schauspielers und Rezitators Mathias Wieman. It can also be helpful to refer to film and theatre director Leopold Lindtberg's comments regarding Wieman.
Wieman was eventually classed as "persona non grata" by Joseph Goebbels, this greatly reduced his activity. He acted in the following movies in the 1940s: Ich klage an, Das andere Ich, Paracelsus, Träumerei and Wie sagen wir es unseren Kindern. After the failed 20 July plot to assassinate Adolf Hitler happened in 1944, Mathias and his wife Erika helped the family of Count Fritz-Dietlof von der Schulenburg. This assistance is detailed by Charlotte von der Schulenburg in the book Courageous Hearts: Women and the Anti-Hitler Plot of 1944 (Dorothee Von Meding, Berghahn Books, 1997).
After World War II he was able to work more intensively in the film business again, normally in support roles. To his fairly well known work belongs No Greater Love, As Long as You're Near Me, The Last Summer, Reifende Jugend, The Girl and the Legend, and opposite Ingrid Bergman in Roberto Rossellini's Fear. Two of the films Mathias starred in were in competition at the Cannes Film Festival: In 1952, No Greater Love; and in 1954, As Long as You're Near Me.
Wieman also made many records (LPs) of classic stories where he would narrate the story accompanied by orchestral music. One example is Peter und der Wolf with Mathias and the Berlin Philharmonic in 1950 conducted by Fritz Lehmann and the Orchestre National de France in 1962 conducted by Lorin Maazel. Another example is Mathias Wiemans kleine Diskothek. In 1992 Deutsche Grammophon issued a commemorative set of CDs in honour of the 100th anniversary of Wieman's birth: Für Kenner & Kinder.
On stage, Wieman appeared in a number of productions including, Goethe's Faust, Pygmalion (play) by George Bernard Shaw, the most famous play of Italian playwright Luigi Pirandello, Six Characters in Search of an Author, and in Bertolt Brecht's In The Jungle of Cities (Im Dickicht der Städte).
His many friends included such diverse people as Hanna Reitsch, Lida Baarova, Hans Fallada, Anny Ondra, and Fritz-Dietlof von der Schulenburg.
After World War II, Wieman moved to Switzerland with his wife, stage actress Erika Meingast, there in 1969 he died of cancer. Mathias and his wife Erika (died in 1972) were cremated and the ashes buried in the Wieman family plot in the Johannesfriedhof cemetery in Osnabrück.
In 1958, his hometown of Osnabrück awarded him the prestigious Justus-Möser-Medaille for his achievements in acting on stage and screen. And in 1965, Wieman received the Bambi Award.