John Bemelmans Marciano

John Bemelmans Marciano (born 1970) is an American author and illustrator best known for the word-history books Anonyponymous: The Forgotten People Behind Everyday Words and Toponymity: An Atlas of Words, and for continuing the Madeline children's book series created by his grandfather Ludwig Bemelmans. He grew up on a horse farm in Three Bridges, New Jersey, graduated from Columbia University in 1992, and lives in Brooklyn, New York.

Anonyponymous (Bloomsbury, 2009) traces the real people behind eponyms, words that look like common nouns but were once someone's name: sandwich, silhouette, boycott, sideburns, and so on. Toponymity: An Atlas of Words (2010), the geographic follow-up, traces words that come from place names, from frankfurter (Frankfurt) and hamburger (Hamburg) to cashmere (Kashmir), tuxedo (Tuxedo Park, New York), bikini (Bikini Atoll), and the German town of Spa. Both books are illustrated with Marciano's hand-drawn maps and witty topical essays.

His continuation of the Madeline series, drawn in his grandfather's watercolor-and-line style, includes Madeline Says Merci, Madeline Loves Animals, Madeline and the Cats of Rome, Madeline at the White House (a New York Times bestseller), Madeline and the Old House in Paris, and others. His first adult nonfiction book, Bemelmans: The Life and Art of Madeline's Creator (1999), is a biography of his grandfather.

His other adult nonfiction includes Whatever Happened to the Metric System? How America Kept Its Feet (Bloomsbury, 2014), a history of the long American resistance to metric measurement. He has also written middle-grade fiction, including The Nine Lives of Alexander Baddenfield (illustrated by Sophie Blackall), the Witches of Benevento series (also illustrated by Blackall), and the Klawde: Evil Alien Warlord Cat chapter book series, co-authored with Emily Chenoweth.