John McLachlan (born 5 March 1964) is an Irish composer.
McLachlan was born in Dublin, son of the poet Leland Bardwell, and studied at the DIT Conservatory of Music and Drama (1982–6), the Royal Irish Academy of Music (1989–97), and Trinity College Dublin (BA 1988), where he received a Ph.D. in musicology in 1999 for a study of the relationship between analysis and compositional technique in the post-war avant-garde. He has also studied privately with Robert Hanson (1989–90) and Kevin Volans (1994–5). He now lives in Inishowen, County Donegal.
He has written numerous articles for The Journal of Music in Ireland (2000–10; now the online Journal of Music). He was executive director of the Association of Irish Composers (AIC; 1998–2012), and in 2007 he was elected to Aosdána.
McLachlan was the featured composer in the RTÉ National Symphony Orchestra's "Horizons" series in 2003 and 2008. He has also represented Ireland at international festivals, including the ISCM World Music Days in Slovenia in 2003 and Croatia in 2005. In 2006, his work Grand Action was commissioned as a test-piece for the AXA Dublin International Piano Competition.
McLachlan's musical aesthetic is largely shaped by a desire to impart a sense of narrative and expectation to his music without recourse to pastiche rhetorical devices. A critic wrote of a recording of McLachlan's piano piece Nine: "The style of each little piece sends one's imagination and musical memory reeling, some of them evoking French Impressionism, some jazzy in feel, some reminiscent of the miniatures for piano of Webern, and none of them in any way, shape or form derivative." Much of his music is structured in contrasting and suddenly changing block-like sections of homogeneous material. The material within these sections is propelled by a rigorous focus on subtle rhythmic and melodic permutations, which result in both surface opacity and gradually increasing tension.