William Rendall Cave (17 June 1842 – 6 July 1916) was a grain merchant and shipowner in the early days of South Australia.
He was a son of Charles Cave (died 1851) of Stoke-sub-Hamdon, South Somerset, and Susannah (1800 – 19 December 1862) who came to Adelaide in 1848 or 1849 and settled at Gumeracha. William found employment with John McKinlay at his cattle station at Lake Victoria, New South Wales. Next the Chambers brothers gave him a job at their northernmost cattle property, Beltana Station, and he remained there for several years, becoming an expert bushman.
He broke in most of the horses used by John McDouall Stuart's 1861 expedition across the continent to Port Darwin. He and John Chambers shod all their horses, and Cave made duplicate sets of horseshoes, possibly at Chambers' Bobmoonie Station where the explorers made their final base before pushing into the unknown. Despite his peripheral association with the Stuart expedition, he was prominent in the many jubilees held between 1883 and 1914.
Early on he went to Port Adelaide and took up stevedoring work for William Younghusband, loading the Solway with the first full cargo of wheat from South Australia for London (perhaps in May 1862), and the Thomas Brown for Acraman, Main, Lindsay, & Co. But after six months on the wharfs he secured a position as overseer of "Thursk", a cattle station near Overland Corner belonging to John White, where he was associated with Sir Jenkin Coles.
After a year at "Thursk" he returned to the Port, working as a shipping and customs clerk with his brother-in-law, James Rawlings (1820 – 27 January 1896). From July 1867 they were trading as Rawlings & Cave, general shipping merchants.
In September 1873 Rawlings left the business, which continued to trade under that name until July 1874, but in October 1873 Cave founded W. R. Cave & Co., with offices at Port Adelaide and Grenfell Street, Adelaide. The business steadily expanded especially in the grain trade, with agencies throughout South Australia and branches in the other States. His partners were his son, John R. Cave, his nephew, Charles H. Warren and for a time Frederick Charles Howard. They became South Australian agents for Howard Smith and Co from ?? to 1893 and McIlwraith, McEacharn & Co Around 1914 the city offices moved to Flinders Street. Rawlings went on to found the very successful shipping agents J. Rawlings & Son.