Ralf Rachbauer was born in Linz, Austria, and studied at the Vienna University of Performing Arts and Cologne Conservatoire. During his studies, he performed at the Städtische Bühnen Münster, the Vienna Volksoper and with the WDR Radio Orchestra. In addition, he appeared at Theater Aachen in roles such as Monostatos in Mozart's "Die Zauberflöte" and Bardolfo in Verdi's "Falstaff". As prize-winner at the Kammeroper Schloss Rheinsberg in Brandenburg International Singing Competition, he sang Pedrillo in Mozart's "Entführung aus dem Serail". He was a guest at the Opéra Bastille in Paris in "Arabella", and sang at Cologne Opera in "Die Meistersinger von Nürnberg", in Prokofiev's "War and Peace", as well as Manol in the new opera "Border" by Ludger Vollmer. He became a member of the Cologne Opera ensembe in 2012/13 season, where he sang roles such as Trabuco in Verdi's "La forza del destino", Jamie/Lord Boxington in "My Fair Lady", Pietro in Franz Schreker's "Die Gezeichneten" and Dr. Blind in "Die Fledermaus".
Previous roles in Wiesbaden include the One-Eyed Man in "Die Frau ohne Schatten", Second Priest / First Armoured Man in "Die Zauberflöte", Kunz Vogelgesang in "Die Meistersinger von Nürnberg", Governor and Ragotzky in "Candide", Fourth Jew in "Salome", Father in "Seven Deadly Sins", Remendado in "Carmen", Footman in "Der Rosenkavalier", Trucker, Doctor and member of the Marshall Family in "Anna Nicole", as well Priest and High Priest in "Babylon" and "Idomeneo" respectively. His roles during the 2022/23 season include Jaquino ("Fidelio"), St. Brioche ("Die lustige Witwe"), Count Hauk-Šendorf ("The Makropulos Affair"), Prisoner ("From the House of the Dead") and Gingerbread Witch ("Hänsel und Gretel").