House of Leaves is the debut novel by the American author Mark Z. Danielewski, published by Pantheon Books. The novel quickly became a bestseller following its March 7, 2000, release, having already developed a cult following through gradual release over the Internet. It was followed by a companion piece, The Whalestoe Letters. The novel has since been translated into a number of foreign languages.

The format and structure of the novel is unconventional, with unusual page layout and style, making it ergodic literature. It contains copious footnotes, many of which contain footnotes themselves, and some of which reference books that do not exist. Some pages contain only a few words or lines of text, arranged in strange ways to mirror the events in the story, often creating both an agoraphobic and a claustrophobic effect. The novel is also distinctive for its multiple narrators, who interact with each other throughout the story in disorienting and elaborate ways.

Danielewski expands on this point in an interview: "I had one woman come up to me in a bookstore and say, 'You know, everyone told me it was a horror book, but when I finished it, I realized that it was a love story.' And she's absolutely right. In some ways, genre is a marketing tool."

House of Leaves has been described as a "satire of academic criticism."