Josias Eduard de Villiers (nicknamed Jos, Koelenhof; 27 December 1843 – 16 August 1898) was a Cape Colony and South African Republic surveyor, politician, and amateur astronomer.
After the resolution of the long-running diamond fields dispute of the 1870s stemming from Sir Henry Barkly declaring the entire area British territory, the Free State appointed De Villiers to define its boundary with Griqualand West.
Sir Joseph Robinson, 1st Baronet surveyed mining claims on Langlaagte Farm where gold would first be found, and he also inspected the 600 plots that made up the spoil tip Randjeslaagte, the seed of Johannesburg, with the help of W.H.A.
The streets ran north to south and east to west artificially, with no regard to terrain, and were quite broad, countering the Transvaal government's expectation of a mere mining hamlet similar to Barberton or Pilgrim's Rest.
Two years later, he was one of 16 killed in a train crash in Mostert's Hoek coming back home from Vryburg, where he had been campaigning for the Parliament of the Cape of Good Hope as a candidate for the Afrikaner Bond.