Biography of X is a novel in the form of a biography. A blend of fiction, nonfiction, and speculative history, the book includes fabricated artifacts as well as intentionally misappropriated texts and images.

Catherine Lacey is the author of three novels, Nobody Is Ever Missing, The Answers, and Pew, as well as the story collection Certain American States. She is a 2019 Guggenheim Fellow and recipient of a Whiting Award. Born in Mississippi, she is now based in Chicago.