Sebastien de Castell had just finished a degree in Archaeology when he started work on his first dig. Four hours later he realised how much he actually hated archaeology and left to pursue a very focused career as a musician, ombudsman, interaction designer, fight choreographer, teacher, project manager, actor and product strategist. His only defence against the charge of unbridled dilettantism is that he genuinely likes doing these things and that, in one way or another, each of these fields plays a role in his writing. He sternly resists the accusation of being a Renaissance Man in the hopes that more people will label him that way.
Sebastien's acclaimed swashbuckling fantasy series The Greatcoats was shortlisted for the Goodreads Choice Award for Best Fantasy. the Gemmell Morningstar Award for Best Debut, the Prix Imaginales for Best Foreign Work and the John W. Campbell Award for Best New Writer. His YA fantasy series Spellslinger was nominated for the Carnegie Medal and is published in more than a dozen languages.

Sebastien lives in Vancouver, Canada with his lovely wife and two belligerent cats.