Austrian-born American novelist whose Menschen im Hotel (1929; “People at the Hotel”; Eng. trans. Grand Hotel) became a best-seller and was adapted as a successful play (1930), an Academy Award-winning film (1932), a film musical (1945; renamed Weekend at the Waldorf), and a Broadway stage musical (1989).

Baum studied music at the Vienna Conservatory but in her teens turned to writing. After a failed marriage and failed finances, she moved to Darmstadt and then to Berlin, where she became employed at the magazine Berliner Illustrierte Zeitung. She had already finished Menschen im Hotel, and it first appeared serially in the magazine. It achieved immediate success in Germany and became one of the most popular examples of the “group” novel, in which a variety of people are thrown together and work out their interrelated destinies. She rewrote it as a play, which Max Reinhardt presented and which, in translation as Grand Hotel, appeared on Broadway. After her New York success, she moved to the United States, becoming a screenwriter in Hollywood in 1932. In 1938 she became an American citizen.

Baum also wrote the novels Men Never Know (1935), Shanghai '37 (1939), Grand Opera (1942), Hotel Berlin '43 (1944), Mortgage on Life (1946), Danger from Deer (1951), The Mustard Seed (1953), Written on Water (1956), and Theme for Ballet (1958).