Meredith was born in Tufnell Park, North London and moved to South Queensferry, Scotland at the age of two. She read for a degree in Music at University of York, where she was awarded first class honours, and gained her master's degree from the Royal College of Music. In 2003, aged 24, she was made the Constant and Kit Lambert junior fellow of the Royal College of Music. Meredith first came to widespread public attention through her work froms created for the 2008 BBC Last Night of the Proms which was broadcast to 40 million people. She has since written another BBC Prom commission, her first opera and collaborated with the beatboxer Shlomo – writing the Concerto for Beatboxer and Orchestra. Meredith has been a judge for BBC Young Musician of the Year, a mentor to Goldie for the TV show Classical Goldie and is a frequent guest and commentator for the BBC Proms and other BBC Radio 3 and 4 shows. She was the classical music nominee for the 2009 Times Breakthrough Award and won the 2010 Paul Hamlyn Foundation Award for Composers. Meredith's pieces include Four Tributes to 4am for orchestra, electronics and visuals by Eleanor Meredith, and HandsFree, a PRS NewMusic20x12 Commission for the National Youth Orchestra, which received warm reviews after being performed as part of the 2012 Cultural Olympiad in the Philharmonic Hall, Liverpool. Alongside her acoustic work, Meredith has made forays into electronic music, which she has performed throughout Europe alongside a diverse range of artists including supporting These New Puritans in Berlin, James Blake, Seb Rochford and Max de Wardener at Ether 2011 and a solo set at La Carrière de Normandoux. In 2012 Meredith released her debut EP, Black Prince Fury, on Moshi Moshi Records, which a reviewer compared favourably to the work of the avant-garde jazz composer Moondog. In August 2013, Moshi Moshi Records and VF Editions released Meredith's second EP, Jet Black Raider. In an interview with Pitchfork, Meredith noted that her second EP featured "clarinets, singing, glocks, drums, lots of cello," unlike Black Prince Fury, which was entirely synthesised. Meredith's debut album, entitled Varmints, was released in March 2016. She featured in the First Night of the 2018 Proms with a new collaboration, Five Telegrams with 59 Productions. Meredith produced the soundtrack for the 2018 film Eighth Grade. She was appointed Member of the Order of the British Empire in the 2019 Birthday Honours for services to music. Her second studio album, Fibs, was released on 25 October 2019. The album was shortlisted for the Mercury Prize 2020.