Harry Neal Baum (17 December 1889 – 7 June 1967) was the third of the four sons of L. Frank Baum and Maud Gage Baum. Baum dedicated The Life and Adventures of Santa Claus to his son Harry. Harry Baum pursued a career in various businesses though his adult life, including hotel management. He also wrote: he collaborated with Olive Beaupre Miller on a quartet of history books for children, The Story of Mankind: A Picturesque Tale of Progress (1929 and after), also called My Book of History. He may have helped his father with the third in the series of Baum's Marie Lousie books, Marie Louise Solves a Mystery (1917).