Born on Vancouver Island, deWitt lives in Portland, Oregon, and has acquired American citizenship.

[5] He left Los Angeles to move back in with his parents in the Seattle area,[6] on Bainbridge Island.

[2] When he sold his first book, Ablutions (2009), deWitt quit his job as a construction worker to become a writer, and moved to Portland, Oregon.

Alongside Edugyan, The Sisters Brothers was also a shortlisted nominee for the 2012 Walter Scott Prize for historical fiction.

[18] His fourth novel, French Exit, was published in August 2018 by Ecco Press, an imprint of HarperCollins.

It follows a retired librarian named Bob Comet and is billed as a "wide-ranging and ambitious document of the introvert's condition.