He was born in Düsseldorf. His vocal studies were guided by Ingeborg Reichelt and Dietrich Fischer-Dieskau. In 1984 he made his debut as Malatesta in Donizetti's Don Pasquale at the Deutsche Oper Berlin and subsequently joined this opera troupe, singing such roles as Guglielmo (Mozart's Così fan tutte), Count Almaviva (Mozart's Le nozze di Figaro), Wolfram (Wagner's Tannhäuser), the Marquis of Posa (Verdi's Don Carlos) and Marcello (Puccini's La bohème).
He has performed as a guest in numerous opera houses: Staatsoper Hamburg, Bayerische Staatsoper in Munich, Wiener Staatsoper, Royal Opera House Covent Garden in London, Opéra National de Paris, Gran Teatre del Liceu in Barcelona, Teatro alla Scala in Milan and Metropolitan Opera in New York, participating in the following operas: Mozart's Die Zauberflöte, Beethoven's Fidelio, Gounod's Faust and Wagner's Tannhäuser. Schmidt has worked with such leading American orchestras as the New York Philharmonic (Kurt Masur), Chicago Symphony Orchestra (Daniel Barenboim), Cincinnati Symphony Orchestra (Jesús López-Cobos), Cleveland Orchestra (Christoph von Dohnányi) and Orchestra of St. Luke's (Sir Roger Norrington). In Europe he has performed with virtually all the more important orchestras, under the baton of such conductors as Claudio Abbado, Vladimir Ashkenazy, Daniel Barenboim, Leonard Bernstein, Herbert Blomstedt, Gary Bertini, Ivor Bolton, Semyon Bychkov, Riccardo Chailly, Colin Davis, Christoph von Dohnányi, Christoph Eschenbach, Rafael Frühbeck de Burgos, John Eliot Gardiner, Carlo Maria Giulini, Bernard Haitink, Nikolaus Harnoncourt, Marek Janowski, James Jordan, James Levine, Kurt Masur, Riccardo Muti, Kent Nagano, Roger Norrington, Seiji Ozawa, Helmuth Rilling, Jukka-Pekka Saraste, Wolfgang Sawallisch, Peter Schreier, Giuseppe Sinopoli, Georg Solti and Christian Thielemann. Intensive concert and recital tours have taken in seventeen European countries, as well as North and South America, Israel and Japan.
Andreas Schmidt often performs in music festivals: in Aix-en-Provence, Salzburg, Edinburgh and Glyndebourne. Since 1996 he has been a guest of the Bayreuther Festspiele, where he has played the roles of Beckmesser (Die Meistersinger von Nürnberg), under Daniel Barenboim and Christian Thielemann, and Amfortas (Parsifal), under Christoph Eschenbach and Christian Thielemann. In June 1997 Andreas Schmidt was awarded the title of Kammersänger Hansestadt Hamburg.
Besides opera and concert engagements, Andreas Schmidt's career has been filled with recitals, in which he has been accompanied by Rudolf Jansen, Geoffrey Parsons, Daniel Barenboim, Jörg Demus, Roger Vignoles and Helmut Deutsch. Among his recordings are three Schubert cycles for Deutsche Grammophon, which received international awards. He has recorded all the songs of Richard Strauss for BMG Classics, awarded the Deutscher Schallplattenpreis in 2000. He has also recorded, for EMI, BMG, Sony, Decca, Philips, Teldec and Hänssler, such works as Brahms's Requiem (Giulini, Abbado), Bach's St Matthew Passion (Gardiner), Mahler's Des Knaben Wunderhorn (Bernstein), Wagner's Tannhäuser (Sinopoli), Offenbach's Les contes d'Hoffmann (Ozawa), Mozart's Le nozze di Figaro (Barenboim), Die Zauberflöte (Norrington and Solti) and Don Giovanni (Norrington), and Beethoven's Fidelio (Haitink). Andreas Schmidt's superb performance artistry has also been documented by numerous recordings for radio and television.