Nicola LeFanu has composed around 100 works for a variety of mediums. Her music is published by Edition Peters and by Novello, and has been widely played, broadcast and recorded. She has composed eight operas, which have been staged in the UK, Ireland and the USA.

She was born in England in 1947 to Irish parents. Her mother was the composer Elizabeth Maconchy. LeFanu studied at the University of Oxford, the Royal College of Music and Harvard University. She is active in many aspects of the musical profession and was Professor of Music at University of York from 1994 to 2008.

In April 2017, she celebrated her 70th birthday and was BBC Radio 3's Composer of the Week. 2017 also saw premieres of five new works, including The Crimson Bird, a dramatic scene with text by John Fuller, commissioned by RPS for the BBC Symphony Orchestra (BBCSO) with soprano Rachel Nicholls.

In 2020, a CD with four of her major orchestral pieces was released by NMC Recordings, supported by a grant from the PRS Foundation. It features the RTÉ National Symphony Orchestra and the BBCSO.

Premieres since the pandemic include a string quintet, Triptych for baritone and chamber orchestra, music for saxophone orchestra and solo works for horn, clavichord and piano.