Born and educated in public schools in Mount Vernon, New York, Davis attended Concordia College, Bronxville in New York, and Fordham University at Lincoln Center, New York City. His first book, Two-Bit Culture: The Paperbacking of America (Houghton Mifflin, 1984) offered an overview and in-depth history of paperback books, although some important publishers, such as Walter Zacharius and Irwin Stein's Lancer Books, were given little or no coverage.
Published by Crown in 1990, Don't Know Much About History spent 35 consecutive weeks on The New York Times bestseller list and sold nearly 1.5 million copies. This unexpected success launched the Don't Know Much About... series. The standardized format is a chronological coverage of a subject with each chapter divided into boldface subheads of questions, such as, "Did Pocahontas really save John Smith's life?" Davis then answers the questions with basic facts delivered in short easy-to-read essays which have a straight-forward approach, but sometimes grab the reader's attention by beginning with light humor and anachronistic comparisons, for example: "Even the astronauts who flew to the moon had a pretty good idea of what to expect; Columbus was sailing, as Star Trek puts it, 'where no man has gone before'." Quotes from historical figures often follow the essays.
The titles were initially inspired by Sam Cooke's song "Wonderful World," with the lyrics, "Don't know much about history" or "geography," etc. Because Davis makes history palatable to bored students, the series has received much praise from teachers and librarians. However, there are occasional negative reviews. When Don't Know Much About History was revised and updated in 2003, Joe Hartlaub wrote a mixed review for Book Reporter:
Davis makes frequent media appearances, including NPR's All Things Considered, and he has lectured at museums, including the Smithsonian Museum and American Museum of Natural History. He has been a contributor to The New York Times, Newsday and other publications.
His current publisher is HarperCollins. In his most recent book, America's Hidden History: Untold Tales of the First Pilgrims, Fighting Women, and Forgotten Founders Who Shaped a Nation (2008), he drops the earlier Q&A format for a more traditional style of writing which he uses to explore little-known aspects of American history. Spanning a period from the Spanish arrival in America to George Washington's 1789 inauguration, these narratives have a more serious tone than the earlier books, are more expansive and focus not only on well-known names but also on forgotten figures such as Hannah Duston. Davis lives in New York City and Dorset, Vermont, with his wife and two children.