William Hillman (13 November 1848 – 4 February 1921) was a British bicycle and automobile manufacturer. In partnership with Louis Coatalen he founded the Hillman-Coatalen Company in 1907, later the Hillman Motor Company after Coatalen's defection to Sunbeam in 1909.
Hillman was born on 13 November 1848 in Stratford, Essex, where his father, also called William, was a shoemaker; his mother was Sarah Stitchbury. He became an apprentice in the engineering works of John Penn & Co. at Greenwich together with his friend James Starley, who became known as "the father of the cycle industry". Hillman and Starley moved to the expanding industrial area of the English Midlands, where they were employed by the Coventry Sewing Machine Company. Sales of sewing machines had declined, and to compensate the company had become the first British manufacturers of bicycles, using designs based on French "boneshakers". The Franco-Prussian War of 1870 halted bicycle manufacture in France and led to a boom in British production. Hillman set up his own bicycle manufacturing company in 1875, Auto Machinery, in partnership with W. H. Herbert, who provided the capital.
As well as bicycles Hillman's company made roller-skates, sewing machines, and ball and roller bearings, of which it pioneered the mass production; Hillman was soon operating four factories in Coventry, and by 1896 a fifth in Germany. His success made him a millionaire, and allowed him to move to Abingdon House, an "impressive home" in Stoke Aldermoor, now a suburb of Coventry.