Tarik Hamilton O'Regan (/ˈtærɪk oʊˈriːɡən/; born 1 January 1978) is a British and American composer. His compositions are partially represented on numerous recordings which have been recognised with two Grammy nominations. He is also the recipient of two British Composer Awards. O'Regan has served on the Faculties of Columbia University as a Fulbright Chester Schirmer Fellow, The Radcliffe Institute of Harvard University as a Radcliffe Fellow, Yale University, Trinity College in the University of Cambridge, Rutgers University, Stanford University as a Visiting Artist, and the Institute for Advanced Study in Princeton as Director's Visitor.

O'Regan's compositions incorporate the influence of Renaissance vocal writing, the music of North Africa, British rock bands of the 1960s and 1970s, jazz and Minimalist music. His music is often rhythmically complex and employs varying approaches to tonality.

Tarik O'Regan was born in London in 1978. He grew up predominantly in Croydon in South London, to an English father of Irish descent and an Algerian mother, spending some of his early childhood in Algeria and Morocco, the latter where his mother was born. He was educated at Whitgift School then Pembroke College, Oxford, where he studied music and, in 1997, he received his first commissions from the Choir of New College, Oxford (conducted by Edward Higginbottom) and James Bowman. During this time, he studied composition privately with Jeremy Dale Roberts.

Following completion of his undergraduate studies in 1999, he began serving as the classical recordings reviewer for The Observer newspaper, a position he held until 2003. At the same time he also worked for JPMorgan Chase, the investment bank. He completed his postgraduate studies under the direction of Robin Holloway at Cambridge, where he was appointed Composer in Residence at Corpus Christi College in 2000 and formally began his career as a composer, with his first published works appearing in 2001 on the Finnish Sulasol imprint.

2002 marked two important London premieres: those of Clichés with the London Sinfonietta and The Pure Good of Theory with the BBC Symphony Orchestra. In 2004, O'Regan moved to New York City to take up the Chester Schirmer Fulbright Fellowship at Columbia University and subsequently a Radcliffe Institute Fellowship at Harvard. During this period, his composition Sainte won the Vocal category of the 2005 British Composer Awards and his debut disc, VOICES was released on the Collegium label.

Beginning in 2007, O'Regan began dividing his time between the UK and the US when he was appointed Fellow Commoner in the Creative Arts at Trinity College, Cambridge, a position he held until 2009. During his tenure at Cambridge, his composition Threshold of Night won the Liturgical category of the 2007 British Composer Awards and Scattered Rhymes, his first CD on the Harmonia Mundi label, performed by the Orlando Consort and the Estonian Philharmonic Chamber Choir conducted by Paul Hillier, was released in 2008.

O'Regan's second disc on the Harmonia Mundi label, Threshold of Night, appeared in late 2008 and awakened a wider interest in his work, demonstrated by the CD garnering two GRAMMY Award nominations in 2009: Best Classical Album and Best Choral Performance. After this, he increased his output as a music commentator in print and on air, especially on BBC Radio 3 and BBC Radio 4. This aspect of his career broadened with the broadcasting in 2010 on BBC Radio 4 of Composing New York, a documentary written and presented by O'Regan. In the same year, he was appointed to the Institute for Advanced Study in Princeton as a Director's Visitor and made his BBC Proms debut with Latent Manifest performed by the Royal Philharmonic Orchestra. O'Regan's third album on the Harmonia Mundi label, Acallam na Senórach: an Irish Colloquy (based on the 12th century Middle Irish narrative of the same name) was released in October 2011.

In 2011, Heart of Darkness, O'Regan's chamber opera in one act, with an English-language libretto by artist Tom Phillips, based on the novella of the same name by Joseph Conrad was premiered at the Linbury Theatre of the Royal Opera House. The idea for the opera first came to O'Regan in 2001. It received wide critical attention and marked his first foray into operatic writing. A suite for orchestra and narrator was extrapolated from the opera and was given its London premiere by the Royal Philharmonic Orchestra and actor Samuel West in April 2013. In May 2015, Heart of Darkness received its North American premiere in a production by Opera Parallèle, presented by Z Space in San Francisco, California.