William Harvey du Cros (19 June 1846 – 21 December 1918) was a Dublin-born financier, the founder of the pneumatic tire industry based on the discovery of John Boyd Dunlop, a Scots-born Belfast veterinary surgeon. Just 65 inches tall and a noted athlete in his youth, he remained an enthusiastic cyclist and a skilful boxer into his middle age. He was briefly a Conservative Party politician of England.