Fergus is the founding artistic director of Irish National Opera and has also worked for all major Irish opera companies. He has conducted a wide-ranging repertoire of 35 different operas. Highlights include Verdi’s Aida , Brian Irvine's Least Like the Other and Rossini's La Cenerentola (Irish National Opera), Wagner’s Tristan und Isolde, John Adams’s Nixon in China, Rossini’s The Barber of Seville (Wide Open Opera), Mozart’s Don Giovanni and, in 2017, Robert O’Dwyer’s Irish-language opera, Eithne (Opera Theatre Company), the first modern performance of the work.
In the orchestral field he has appeared with the RTÉ Concert Orchestra, the Ulster Orchestra, the Irish Chamber Orchestra and other orchestras at home and abroad. He has toured the RTÉ National Symphony Orchestra throughout Ireland in Beethoven’s Choral Symphony and Mahler’s Resurrection Symphony. As a choral conductor he has worked with the State Choir Latvija (giving the world premiere of Arvo Pärt’s The Deer’s Cry) and the BBC Singers. Internationally he has fulfilled engagements in the USA, Canada, South Africa, Australia, the UK, France, Netherlands, Denmark, Sweden, Malta and Estonia.
Before founding Irish National Opera he led both Wide Open Opera (which he founded in 2012) and Opera Theatre Company. Since 2011 he has been responsible for the production of 37 different operas, which have been seen around Ireland as well as internationally in London, Edinburgh, New York, Amsterdam and Luxembourg.