（born 1 January 1978) is a British and American composer.His compositions number over 100 and are partially represented on 43 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, 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.