Nicholas Day

Nicholas Day (born 1991) is an American author of narrative nonfiction for children and adults, best known for his middle-grade book The Mona Lisa Vanishes (2023), which won the Robert F. Sibert Award and the Boston Globe-Horn Book Award for nonfiction, chronicling the theft of the famous painting and its rise to global fame. Other notable works include the picture book Nothing: John Cage and 4'33", the adult book Baby Meets World on the science of infancy, and A World Without Summer (2025) about the Year Without a Summer. He contributes to publications like Slate, The Atlantic, and The New York Times, and lives in Western Massachusetts.Nicholas Day official site.