Gwyn Pritchard was born in Yorkshire in 1948.  He started composing at the age of twelve, and in 1966 entered the Royal Scottish Academy of Music where he studied the 'cello and composition.  During his student years he wrote a Viola Concerto, and other works which still receive regular performances, most notably Music for Doublebass & Harp (included on a portrait CD on the Sargasso label).  After a short period as Director of Music at Salisbury Cathedral School he worked as a freelance 'cellist in London, and was then employed by the BBC, firstly as an orchestral 'cellist, and later to be the subject of a documentary film Young Composer for which he was commissioned to write Spring Music. 

For a brief period he divided his time between composing and working as a ‘cellist, but in the late 1970s, after performances of Objects In Space and Mercurius at London's South Bank brought his work to the attention of a wider public, he decided to commit himself exclusively to composition and conducting. Since then much of Pritchard's compositional activity has been based outside the UK.

In 1979 Nephalauxis was performed at the Warsaw Autumn Festival.  This was the beginning of a fruitful musical relationship with many Polish musicians and festivals that was to develop over the following years, culminating in his being a Featured Composer alongside Lutoslawski at the International New Music Week held in Southampton at which several of his works were performed, including the première of the major orchestral piece La Settima Bolgia. 

In 1982 he founded Uroboros Ensemble which includes some of Britain's leading instrumentalists.  He has composed several pieces for the group, including Moondance, Lollay-Lollay, Chamber Concerto, Madrigal and most recently Features and Formations.  As their conductor he has performed and broadcast with them throughout Britain and abroad, and as their Artistic Director has commissioned several new works, and introduced much unfamiliar music from other countries to British and other audiences in Europe.

Since the early 1990s Pritchard has developed an ongoing association with leading instrumentalists based in Switzerland (mostly in Basel) for whom he has composed a number of substantial pieces: Janus, Wayang, Break Apart, Demise (which involved him for the first time in electronics), culminating in the 'cello concerto The Fruit of Chance and Necessity which was performed in Basel at the 2004 ISCM World New Music Days.  His lighthearted theatrical birthday tribute to the Basel Percussion Trio Das Mysterium der Heiligen Dreifatligket was incorporated into La Revue Burlesque by the famous Teatro Dimitri which toured in numerous countries in the late 1990s.  More recently the Basel Symphony Orchestra promoted a concert which, to celebrate Pritchard's sixtieth birthday, included two of his works, and Conflux was toured extensively throughout Switzerland by the ensemble Quadriga.  He has also conducted Swiss groups including The Basel Soloists touring Britain and Canada, and Ensemble Interplay in Italy.

Italy has also figured prominently in Pritchard's career.  In 2003 he founded the Reggello International Festival of Contemporary & Classical Music in Tuscany, and as Artistic Director invited ensembles and soloists from many parts of the world to participate, often programming music which is seldom heard in Italy.  He also directed the RIF Composers' Competition, hosted by the festival.  In 2008, to mark his sixtieth birthday, Pritchard was one of very few composers represented in a major concert series in Florence to celebrate Elliott Carter's hundredth birthday; and the same organisers have continued to include Pritchard's work in their summer concert series in Florence in subsequent years.  In Venice in 2011 Ex Novo Ensemble commissioned and gave the première of Nighfall.

In recent years Pritchard has been the recipient of a number of commissions and performances in Germany and Austria, including Song for Icarus and Ariel Dreaming, both commissioned for the Weimar Spring Days for Contemporary Music.  Since 2008 he has returned annually to this festival as composer, conductor and competition judge.  A special concert in Essen celebrated Pritchard’s sixtieth birthday (along with other composers' decennial anniversaries) by programming all his shorter works for piano.  His music has been represented regularly at the Zepernicker Randspiele and other German festivals and concert series, many of them in or near Berlin, which is also the home of  Pritchard's main publisher, Verlag Neue Musik.  In November 2011 three 'portrait' concerts dedicated entirely to Pritchard's music were given in Salzburg by members of the Österreichisches Ensemble für Neue Musik (oenm); the piano trio Res which was composed especially for the occasion was repeated at the Wien Modern festival.

Pritchard's music is performed around the world. It has been represented at major international festivals such as Warsaw Autumn, Wien Modern, Huddersfield, International New Music Week, ISCM World Music Days, Weimar Frühjahrstage and numerous others.  It has been performed in many European countries, in the USA, Canada, China, South Korea, Hong Kong, Australia, New Zealand, and of course throughout Britain.  It has also been widely broadcast, often under his own direction, on many radio and television networks.  In recent years The Firmament of Time was commissioned by the BBC and performed by the BBC Symphony Orchestra in 2009.  He also has recently completed a work for the Dutch group Orkest 'de ereprijs' entitled Harmoniemusik, a piece entitled In the Silence of Turned Earth for soprano and violin soloists with string orchestra, composed for the Sofia Soloists in Bulgaria, Kommos for Ensemble Eclat of S Korea, and Nighfall for Ex Novo Ensemble of Venice.

Pritchard is a professor of composition at Trinity Laban Conservatoire of Music and Dance in London.  As a teacher and lecturer he has been invited to many academic institutions, including The Royal Academy of Music, The Birmingham Conservatoire, The Basle Conservatoire, The Eastman School of Music and several universities in Britain and American.  He has also taught composition extensively to private students and in workshops in Britain and abroad.  He has written, introduced and participated in programmes for BBC Radio 3, and has contributed articles and reviews to a variety of musical publications.