The bass-baritone Hanno Müller-Brachmann, who grew up in southern Baden and received his early musical training with the Basel Boys' Choir, studied with Ingeborg Most in Freiburg and Rudolf Piernay in Mannheim, and attended the Lied class of Dietrich Fischer-Dieskau in Berlin. While still in training, Daniel Barenboim brought the 27-year-old three-time competition winner to the Berlin State Opera Unter den Linden, where he remained a member of the ensemble for 13 years. There, Hanno Müller-Brachmann embodied the great Mozart roles of his field. Additionally, he was heard as Kaspar (Der Freischütz), Amfortas (Parsifal), Escamillo (Carmen), Banquo (Macbeth), Goulaud (Pelléas et Mélisande), and the Count (Der ferne Klang), as well as in the world premieres of Elliott Carter's What Next? and Pascal Dusapin's Faustus, the Last Night. Alongside Daniel Barenboim, other significant partners at the conductor’s podium in Berlin included Michael Gielen, René Jacobs, Sebastian Weigle, Gustavo Dudamel, Pierre Boulez, Sir Simon Rattle, and Philippe Jordan.

Guest performances also took Hanno Müller-Brachmann to the state operas of Hamburg, Vienna, and Munich, the Theater an der Wien, and to San Francisco. The recording of Mozart's Zauberflöte in Modena under the baton of Claudio Abbado, with Hanno Müller-Brachmann in the role of Papageno, was released by Deutsche Grammophon and won a "Gramophone Award" for Opera Recording of the Year. In Cleveland, he recently sang Golaud in Debussy's Pelléas et Mélisande and the Music Master in Ariadne auf Naxos under the baton of Franz Welser-Möst. Influential directors for him have included Harry Kupfer, Peter Mussbach, Martin Kušej, Doris Dörrie, Keith Warner, and Peter Sellars.

As a concert singer, the bass-baritone experienced unforgettable moments in performances under the baton of Adam Fischer, Daniel Harding, Gianandrea Noseda, Andris Nelsons, Vladimir Jurowski, Kirill Petrenko, and Sir Simon Rattle. He had a long-standing collaboration with Bernard Haitink, with whom he worked at the Chicago Symphony Orchestra, the Concertgebouw Orchestra Amsterdam, the Orchestra of La Scala in Milan, and the Bavarian Radio Symphony Orchestra. With this orchestra under the baton of Mariss Jansons, he sang the 2017 world premiere of Wolfgang Rihm's Requiem Strophes.

As a song recitalist, Hanno Müller-Brachmann has performed at London's Wigmore Hall, the Vienna Konzerthaus, and at festivals such as the Schubertiade Schwarzenberg, Edinburgh, Hitzacker, Lockenhaus, Mecklenburg-Vorpommern, and Schleswig-Holstein. 

The most recent CD release is the song album Brahms Songbook, Vol. 2 together with Dame Sarah Connolly and Malcolm Martineau. In 2022, the album “Auf jenen Höh’n” was released, featuring Mahler's Kindertotenlieder, Martin's Jedermann Monologues, and Brahms' Vier ernste Gesänge with Hendrik Heilmann on piano. In 2021, a recording of Schubert's Schwanengesang and early songs by Carl Maria von Weber, accompanied by Jan Schultsz on the fortepiano, was also released. His recording of songs by Rudi Stephan with Hinrich Alpers on piano was awarded the "Opus Klassik."

Hanno Müller-Brachmann teaches as a professor of singing at the Hochschule für Musik Karlsruhe. He serves as a juror for international competitions and the German National Academic Foundation and is passionately committed to the preservation and improvement of musical education, currently serving as chairman of the Cantus Juvenum Karlsruhe boys' and girls' choir e.V..