William Alvin Bowen (May 15, 1877–September 18, 1937) was an American attorney who wrote several children's books in the 1920s. His most notable work was The Old Tobacco Shop, a fantasy novel that was one runner-up for the inaugural Newbery Medal in 1922.

Bowen was born in Baltimore, Maryland, earned a Bachelor of Laws degree from the University of Maryland in 1898, and worked in his father's law office until 1904, when he moved to Los Angeles. There he was a member of the Olympic Committee as attorney for the 1932 Summer Olympics. He was also a member of the California and Southern California Historical Societies.

Bowen's first children's book was The Enchanted Forest, a fantasy novel published by Macmillan late in 1920. His second was The Old Tobacco Shop, one year later.