The most venomous spider found in Africa is the Six-eyed sand spider (Sicarius hahni). It is found in deserts and sandy areas of southern Africa, including Namibia, South Africa, and Botswana. The venom of this spider is highly potent and can cause serious health problems, including tissue death and renal failure. However, despite its potent venom, the Six-eyed sand spider is not considered to be highly dangerous to humans, as it is not aggressive and rarely comes into contact with people.