Niall studied piano and composition at the Royal Irish Academy of Music. He was awarded first prize at the 1992 Dublin Film Festival's music competition, chaired by composer Michael Nyman. Since then he has composed music for films, animation and television drama.
Recent film credits include the psychological thriller 'In Darkness' starring Natalie Dormer. Recent television dramas include the BAFTA award-winning ITV drama series 'Little Boy Blue', the forthcoming ITV drama series' 'Hatton Garden' and the critically acclaimed UK drama series ‘Manhunt’. ‘Manhunt’ premiered in January 2019 and was ITV's highest rated new drama since the launch of ‘Broadchurch’ in 2013.
Niall has received several IFTA Award nominations and won the IFTA award for Best Original Score in 2013 for his score to the BBC film 'Loving Miss Hatto'. In 2018 he received the Venus award for his score to the animated film ’The Lost Letter’ at the Badalona Film Festival in Barcelona. His orchestral score for the classic Irish silent film ‘Guests of the Nation’, commissioned by the Irish Film Institute, has been performed by the RTE Concert Orchestra in Dublin, New York (Lincoln Center) and London (Barbican).
Niall also writes piano music and has released three solo piano albums. Two of these albums ‘The Promenade’ and ‘Still Life’ are released by the contemporary classical label 1631 Recordings. His third piano album ‘Nightsongs’ is published independently. In 2019 Niall signed with Faber Music publishing in London.