Károly Szemerédy made his house debut at Opéra national de Paris as Dr Kolenatý in Krzysztof Warlikowski’s staging of The Makropulos Affair under the baton of Susanna Mälkki and gave further performances in the role at Grand Théâtre de Genève under Tomáš Netopil, and in a new production by Richard Brunel for Opéra national de Lyon, conducted by Alexander Joel. As Orest in Elektra, appearances include at Bayerische Staatsoper under Vladimir Jurowski, at Grand Théâtre de Genève conducted by Jonathan Nott, at the Concertgebouw as part of the NTR Zaterdag Matinee series under Markus Stenz and at Teatro Real conducted by Semyon Bychkov, and as Šiškov he appeared at Opéra national de Lyon under Alejo Pérez. Most recently, he debuted in the roles of Sacristan, Lunobor and Domšík in The Excursions of Mr Brouček at Bregenzer Festspiele, in a new staging by Yuval Sharon, and conducted by Robert Jindra.

Awarded the Hungarian Gold Cross of Merit in 2023 in recognition of his dedication to the promotion of Hungarian music and culture, Károly Szemerédy is a regular guest on the stage of Hungarian State Opera. His performances there include as Telramund in Lohengrin and Gunther in Götterdämmerung under Adam Fischer, as Don Pizarro in Tobias Kratzer’s staging of Fidelio, as Renato in Un ballo in maschera, Michele in Il tabarro and Scarpia in Tosca under Gergely Kesselyák, as Vodník in Rusalka under Péter Halász, as Yeletsky in Pique Dame under Balázs Kocsár, and as Don Giovanni, Conte Almaviva in Le Nozze di Figaro and Escamillo in Carmen.