Proinnsías Ó Duinn was born in Dublin, Ireland. He studied ‘cello, piano and orchestration at the Royal Irish Academy of Music and the College of Music in Dublin, Ireland. His first professional conducting engagement was in 1957 at the age of sixteen. Two years later, he was appointed Music Director of the Gaiety Theatre in Dublin.

1959: Invited to conduct the RTE Symphony Orchestra (now called the National Symphony Orchestra of Ireland), begining a long ongoing professional relationship.

1961: Awarded a Fellowship by the Irish Arts Council.

1963: Appointed Principal Conductor of the Iceland Symphony Orchestra.

1965: Appointed Principal Conductor of the Orquesta Sinfonica Nacional del Ecuador.

1971: Returned to Ireland to work with the National Symphony Orchestra, the RTE Concert Orchestra (Orchestra of the Irish National Radio and Television Broadcasting Organization, www.rte.ie), the Irish Chamber Orchestra and the BBC. He also conducted extensively in various countries of Europe. During his tenure with the orchestra, Ó Duinn was the prime mover in them becoming one of the most versatile orchestras of its kind in Europe, with a vast repertoire covering almost every genre. He toured extensively with his orchestra throughout Ireland, Great Britain and the United States. He recorded with the orchestra on the Marco Polo, Naxos and other labels. His repertoire includes many National and World Premieres, from Eurovision to the music of Bill Whelan ("River Dance" and "Seville Suite") to the symphonies of John Kinsella.

• 1971: Review, Irish Times, Mahler #1: "Quite clearly, Mr Ó Duinn had authority. He knew what he was doing and knew what he wanted - and got it with clarity and no fuss. He had the air of being willing to, and knowing that he could, trust his players as artists without unnecessary and annoying gestures."
• 1973: Review, Irish Times, Sibelius #2: "Proinnsías Ó Duinn has of course a rather special understanding of strings: he can mould phrases so that the speed fits the players' breathing and bow length like a glove; this knack or skill makes it very rewarding and satisfying to play with and for him. Add to that the ability to play a romantic work such as the Sibelius with such musical feeling that one wanted to sing the tune with him."

1974: Appointed Vocal Advisor to the Irish Radio and Conductor of the RTE Chamber Choir. In 1976, he received the Radio and Television critics’ award for “the quality of his work and his inventive approach to programming”.

1978: Appointed Permanent Principal Conductor of the RTE Concert Orchestra, a position he held until 2003.

1979: Appointed Music Director and Conductor of Dublin’s leading Choral Society, Our Lady's Choral Society (www.olcs.ie) a position he still holds. Their annual season of Messiah performances in the National Concert Hall each Christmas has become a focal point of the music calendar in Dublin.

1980: Composed and conducted the soundtrack for the seven hour television drama series. (reissued in DVD format in 2007).

1984: Founding Board Director and first Music Director of Opera Theatre Company, Ireland.

1986: Appointed to Board of Directors of Cork City Opera, Ireland.

• 1990: Review, Irish Times, Bruckner #9: "He is still one of the most inspirational conductors working regularly with any Irish orchestra."

2001: Composed, orchestrated and conducted the premiere of his musical “Stuff and Nonsense” (based on the life and verses of Edward Lear)

2002: Contracted to conduct the annual Handel “Birthday Celebration” performances in the Handel Concert Hall in Halle, Germany, a position he still holds. This annual celebration of Handel's birth in Halle features an international choir, soloists and the Staatskapele Halle. (www.happy-birthday-handel.org)

2003 Appointed to Board of Directors of the Contemporary Music Centre of Ireland. (www.cmc.ie)

2003: Appointed the first Conductor Laureate in the history of RTE.

To date: Proinnsías Ó Duinn continues as Music Director of OLCS with acclaimed performances of Verdi “Requiem” and Elgar’s “Dream of Gerontius” in 2023. He maintains close working relationships, conducting both the National Symphony Orchestra and the RTE Concert Orchestra. He also continues to conduct the annual birthday celebration performance of “Messiah” in Handel’s birth city of Halle. Apart from his conducting career, Proinnsías is also known as a composer and orchestrator. He has composed for Orchestra, Chamber Music, Theatre and TV.