Mark Haddon was born in Northampton, England, in 1962. He graduated from Merton College, Oxford, in 1981, and later returned to his studies at Edinburgh University, where he received a Master’s degree in English Literature. After school, Haddon took a number of odd jobs, including one working with children who had physical and mental disabilities, including autism. He also worked as an illustrator and cartoonist, contributing to a number of prominent British publications. In 1987, Haddon published his first book, Gilbert’s Gobstopper, about a piece of candy that, over the course of fifty years, gets bounced around the world until it returns to Gilbert, the boy that dropped it (he is an old man by the time it returns). Haddon followed with more than a dozen works for children over the years, many of which he also illustrated, and became involved in writing for children’s television. For the British children’s show, Microsoap, in particular, Haddon won multiple awards, including the Royal Television Society’s honor for Best Children’s Drama.

In 2003, Haddon published The Curious Incident of the Dog in the Night-time, his first foray into adult fiction. The book follows Christopher John Francis Boone, a young boy whose symptoms and behavior suggest he has a mild form of autism, perhaps Asperger’s Syndrome. The book came out in England in two imprints, one aimed at young adults, and one at adults, though no differences separate the two editions other than a slight change in the cover artwork. Haddon’s novel immediately won fans in each group, quickly selling more than a million copies in both markets, in no small part because of the unique voice of its narrator. The book earned critical acclaim as well, receiving praise from outlets like the New York Times and from noted authors including Ian McEwan. To date, The Curious Incident of the Dog in the Night-time has been published in more than thirty-five countries and has become an international best seller. In the United Kingdom, Haddon’s book has sold more than 2.6 million copies, making it the third best-selling book of the decade.

Had The Curious Incident of the Dog in the Night-time come out ten years earlier, it might have had a difficult time finding grown-up readers. In the early 1990s, few novels about young protagonists found success with adults. But the immense popularity of J.K. Rowling’s Harry Potter books, and to a lesser degree Phillip Pullman’s “His Dark Materials” series, both of which featured young protagonists coming of age against the backdrop of a dramatic storyline, helped change the way audiences received stories about young adults. Both series achieved popular as well as critical success, with Rowling’s books in particular becoming some of the biggest sellers of all time. Even though Rowling and Pullman wrote their books for younger audiences, while Haddon wrote his for adults, Haddon’s novel found the same kind of crossover appeal. Reflecting this success across age groups are the numerous awards the book has won, which include the Whitbread Book of the Year Award, the Guardian Children's Fiction Prize, and the Booktrust Teenage Prize.

Despite his work with autistic children, Haddon staunchly asserts that he is not an authority on autism and claims to have done very little research on the subject before writing the novel. In an interview with Powell’s Books, Haddon said that when he worked with autistic children, “autism wasn't a term that was even used much at the time, and only in retrospect do I realize that some of the people I worked with had autism, although they had it much more seriously than Christopher does.” Although the novel never mentions autism, Christopher, the novel’s protagonist, displays several of the symptoms that characterize the disorder, such as difficulty reading facial expressions, preoccupation with certain topics, and behaviors like rocking back and forth. Additionally, many of the press releases put out by the publisher, as well as the packaging of certain editions of the book, describe Christopher as autistic. The autistic community has criticized the book for offering an inaccurate depiction of the condition. Haddon, however, says he intended his book only as a work of fiction and not a medical treatise on living with autism.