Benjamin Ward Baum (3 January 1821 – 14 February 1887) was L. Frank Baum's father.
He was of German descent, the oldest son of John Baum and the former Magdalena Elwood, and the second of their ten children. John Baum had been a prosperous farmer, but suffered financial reverses and later became a Methodist lay preacher; he was known as Reverend Baum.
Benjamin Ward began life as a poor cooper (barrel maker). His lack of means displeased his prospective father-in-law, Oliver Stanton; Benjamin and Cynthia Stanton eloped and married on 10 March 1843, when both were 21 years old.
Over time, Benjamin proved to be an astute businessman. He branched out from the cooperage craft to related trades — butter and cheese on one hand, and the oil industry on the other. In 1850 he was in the pump vending business, in partnership with a brother-in-law. He settled his family in Chittenango, New York in 1853, where he invested in real estate and built a barrel factory. He was active in the oil industry that began in nearby Pennsylvania in 1859. In 1863 he established the Second National Bank of Syracuse; in 1866 he started Neal, Baum & Company, a dry goods wholesaler. He used his businesses to employ his younger brothers, and later his new son-in-law William H. H. Neal. Another business, a lubricating oil concern, provided employment for two of Benjamin Ward's sons, Benjamin William Baum and L. Frank Baum, in the 1880s.
The elder Baum's oil business ran into difficulties in the later 1870s, when he organized opposition to John D. Rockefeller's Standard Oil Company. He recovered by the early 1880s, however, and remained prosperous until his health broke later in the same decade. He went to Germany for medical treatment, then returned home, to die early in 1887.