Frederick William FitzSimons (6 August 1870 Garvagh, Ireland – 25 March 1951 Grahamstown),[1] was an Irish-born South African naturalist, noted as a herpetologist for his research on snakes and their venom, and on the commercial production of anti-venom.

Shortly afterwards I examined it in Port Elizabeth, and, impressed by the huge size of the brain, the great thickness of the bone—in places 15 mm.—and certain remarkable features in the jaw, I thought it worthy of specific rank and named it Homo capensis.

[citation needed] FitzSimons' anthropological work also included studies of the coastal Bushmen or Strandlopers who were ultimately displaced by the Khoikhoi.

From this he became a published authority on South African snakes and their venoms and he patented a (now outdated) first-aid and serum treatment kit.

[1] His son Vivian Frederick Maynard FitzSimons (1901-1975) became director of the Transvaal Museum in 1947, had a particular interest in South African reptiles, and helped establish the Namib Desert Research Association.