United States Benjamin Johannes "Ben" Viljoen (7 September 1869 – 14 January 1917)[2] was an Afrikaner-American consul, soldier, farmer, Maderista, and Boer general.

He led the Johannesburg Commando, the great nemesis of the Uitlanders and he fought at the Battle of Elandslaagte on 21 October 1899, where he narrowly escaped capture by the British.

After the fall of Johannesburg on 31 May 1900 he fought in the Battle of Diamond Hill (Afrikaans: Slag van Donkerhoek) on 11 and 12 June 1900 in central Transvaal.

[6] With the end of the conventional phase of the war, he formed a powerful guerrilla commando consisting of men from Johannesburg, Krugersdorp, Boksburg and the North and East Transvaal.

Viljoen's exploits included surprising a garrison at Helvetia in the Eastern Transvaal on 29 December 1900 and temporarily capturing 235 men and a 4.7-inch gun.

[8][9] In April 1901 Viljoen narrowly escaped capture by Lieutenant-General Sir Bindon-Blood and in August 1900 he protested to the same Blood about the use of blacks in the war.

He returned to South Africa as a pauper but refused to take British citizenship, thus greatly reducing his chances of resuming a public career.

Ben Viljoen was one of the South African refugee officers who formed a farm colony in Mexico with the assistance of Theodore Roosevelt.

He divorced his wife, Lenie (née Els), who did not really want to leave South Africa, when the news reported he was engaged to May Belfort.