Major Sir William Cornwallis Harris (baptised 2 April 1807 – died 9 October 1848) was an English military engineer, artist and hunter.
The son of James Harris of Wittersham, Kent, he entered Addiscombe Military Seminary at the age of fourteen. Two years later, in December 1823, he joined the army of the East India Company as second lieutenant in Engineers, Bombay Establishment. Over the following thirteen years, he was posted to several places in India and was able to pursue his taste for field sports and the depiction of wildlife. He was promoted to first lieutenant in 1824 and to captain ten years later.
In June 1836, Harris arrived at Cape Town on the 1467-ton Buckinghamshire and stayed for two years in order to recover from a fever. He was fortunate to meet Dr. Andrew Smith, freshly returned from a journey north on which he had visited Mzilikazi at Mosega. From the Cape, he arranged a hunting trip, which was to last from 1836 to 1837, to the Western Transvaal and Magaliesberg with William Richardson of the Bombay Civil Service, who had been a fellow passenger on the voyage.
They sailed to Algoa Bay and made their way to Grahamstown, where they outfitted their expedition and received helpful advice from the ivory traders David Hume and Robert Schoon. Their route took them across the Orange River to Kuruman, where they met Robert Moffat, who had befriended Mzilikazi and was able to provide Harris with useful information about the ruler. Mzilikazi received Harris' presents with pleasure and the expedition set off confidently for the Magaliesberg toward the south-east.
Here they experienced at first hand the struggles of the Voortrekkers against the Matabele. Harris came across his first sable antelope (Hippotragus niger) in the Magaliesberg, and sent a description and specimen of the animal to the Zoological Society of London. David Hume had years earlier decided that it was possible to cross the Kalahari and reach Lake Ngami. Harris was of like mind and made known his willingness to go, but the geographical societies of Bombay and London ignored him.