Born in London, England, at age seven he sang in the boys' choir at Westminster Cathedral.
He has since scored a diverse range of popular films, including both Charlie's Angels[1] outings, Cruel Intentions, Species II, and K-PAX.
[1] In 2023 he composed the soundtrack for the film adaptation of Ernest Hemingway's last novel Across the River and into the Trees.
In addition to his film work, Shearmur has collaborated as keyboardist and arranger with a number of prominent rock musicians, including Eric Clapton, Peter Gabriel, Annie Lennox, Pink Floyd, Marianne Faithfull, Bryan Adams, Echo & the Bunnymen, and Jimmy Page and Robert Plant.
Ambient artist David Helpling has cited Shearmur's compositional style as a major influence on his work.