Nwanoku was born in London to Nigerian and Irish parents and grew up in the UK, but spent two years in Imo State, Nigeria. At aged seven she took up classical piano, and aged eight she began training as a 100-metre sprinter. Her athletics career ended at 18 due to a knee injury and she took up music full-time, studying the double bass.
Nwanoku graduated from the Royal Academy of Music in London with the Principal’s Prize and the Eugene Cruft Double Bass Prize, and was awarded four scholarships, including the Royal Society of Arts. This allowed her to undertake further study with Franco Petracchi in Rome.
Her musical accomplishment includes being named a Fellow of the Royal Academy of Music in 1998, and awarded an MBE for Services to Music in the Queen's Birthday Honours 2001. She is Professor of Double Bass Historical Studies at the Royal Academy of Music, a visiting Professor at Double Bass at Trinity College of Music in London, a founding member and principal bass with the Orchestra of the Age of Enlightenment, and a regular guest with string quartets and chamber groups.
In the media, she has been involved with programmes on BBC Radio 3 including the BBC Radio 3 Requests programme where she alternates with Fiona Talkington. She has also appeared on television as a permanent guest at the BBC Proms, and has written blogs for The Guardian and elsewhere. She was a judge on BBC television's competition Classical Star in 2007.
- London Gazette, 16 June 2001