Irish mezzo-soprano Niamh O’Sullivan has been praised for her “bewitchingly beautiful, dark vibrant voice” (Süddeutsche Zeitung). A BBC Radio 3 New Generation Artist from 2023 to 2025 and former studio member of the Bayerische Staatsoper, Niamh has quickly established herself as one of the most exciting mezzos today.

The 2024–25 season saw Niamh make a series of debuts, including her house and role debut as Ino (Semele) and role debut as Octavian (Der Rosenkavalier) for Théâtre des Champs-Élysées, and role debuts as Ursule (Béatrice et Bénédict) and Maddalena (Rigoletto) for Irish National Opera. She also sang Ino in her return to the Royal Opera House.

In the 2023–24 season, Niamh made her role debut as Wellgunde in a new Barrie Kosky production of Das Rheingold at the Royal Opera House, and as Carmen in La tragédie de Carmen at the Buxton Festival, in addition to singing Wellgunde in Das Rheingold and Götterdämmerung and Mercédès in Carmen for Opernhaus Zürich.

Other recent plans have included Meg Page (Falstaff) at Opernhaus Zürich, Mercédès at English National Opera, and Mirza (Lalla-Roukh) and Paulina (Ein Wintermärchen) with Wexford Festival Opera. Niamh’s close association with Irish National Opera has seen her sing Charlotte (Werther), Mercédès, Tisbe (La Cenerentola), Third Maid (Elektra), Asteria (Bajazet), and Alva in the world premiere of The First Child for the company.

In concert, Niamh has performed Elgar’s Sea Pictures at the Prinzregententheater for the Munich Festspiele, Mozart’s Requiem and Handel’s Messiah with the Münchner Hofkantorei, the main role of Cain in Scarlatti’s Il primo omicidio with the Munich Jakobsplatz Orchestra conducted by Daniel Grossmann, Cousser’s The Universal Applause of Mount Parnassus at the Wigmore Hall with Ensemble Marsyas conducted by Peter Whelan, and Messiah with the Ulster Orchestra.

As a member of the Opera Studio at the Bayerische Staatsoper from 2016 to 2018, Niamh sang numerous roles including Hänsel (Hänsel und Gretel), Kate Pinkerton (Madama Butterfly), and the Secretary (The Consul).

Niamh studied at the Royal Irish Academy of Music in Dublin and was a participant of the Académie du Festival d’Aix-en-Provence in 2023.