William Mills Donaldson (March 14, 1840 - October 22, 1931) was an American businessman and lithographer. Born in Cincinnati, Donaldson's father died when he was a few months old and his mother died when he was ten. He was a sickly child but sought an education, mostly at the encouragement of his grandfather. In the late 1850s, when his uncle (who was in charge of his estate) forbade him entering medical school because it was too expensive, Donaldson left school and found work at Middleton-Wallace and Company, a lithographer in Cincinnati. Middleton-Wallace closed in December 1860, but reopened in January 1861. Donaldson went into business for himself in 1863, opening a lithographic firm with his close friend and fellow lithographer Henry Elms, with Donaldson as the senior partner. Then, in 1864, Donaldson decided to begin printing chromolithographs, which caused the firm's success to grow exponentially. By 1868 they had been forced to relocate twice because of a need for bigger premises. Henry Elms died in 1872, leaving Donaldson to run the business on his own. Nonetheless the firm continued to grow and prosper. Donaldson used this success to further expand the business and began framing as well. Donaldson sold the Donaldson Lithographing Company to the Consolidated Lithographing Company in 1905.