Black widow- lives in Australia.

It is either the wandering spider of brazil or the funnel web spider of australia. It is generally considered to be the funnel web spider, but the wandering spiders venom is a little more potent than the funnel webs but comes into contact with much much less people.

The deadliest spider on earth is arguably the six-eyed sand spider (Sicarius hahni), a secretive, fast-moving hunting spider indigenous to the deserts of Southern Africa. A brownish, medium-sized spider, Sicarius (Latin for "assassin," or "murderer") resembles some of the common wolf spiders found throughout Europe and the Americas, only slightly lighter in color. The legs are canted in a crab-like fashion similar to that of some species of North American huntsman spiders. Much has been made of the toxicity of the the brown and Chilean recluses (Loxosceles reclusa/laeta), and the ferociously aggressive Sydney funnel web spider (Atrax robustus); and the Guinness Book of World Records lists the Brazilian wandering spider (Phoneutria fera) as having the deadliest neurotoxin of any spider. The venom of none of these, however, appears to be a match for that of Sicarius hahni, which may be the most cytotoxic (i.e., cell-destroying) venom of any living thing. The chemical mechanism of Sicarius venom isn't completely understood, however it may be the closest biological equivalent of the fictional "molecular acid" exuded by the face-hugging creature in "Alien." Laboratory rabbits injected with small amounts of S. hahni venom were dead within hours; dissection of the animals revealed catastrophic destruction of the subcutaneous tissue and vital organs. In spite of the horrendous effects of its venom, the statistics suggest that this deadliest of spiders is among the least likely to bite a person, presumably because of its shy nature and historical avoidance of human contact. In the long history of habitation on the African continent, bites from these spiders are extremely rare, which is a good thing. In the two suspected cases of human envenomation by this spider, one resulted in death due to internal hemmorhaging and organ failure; the other resulted in the loss of an arm due to massive necrosis (tissue death) in the vicinity of the bite. Colloquial wisdom for desert travellers advises the amputation of a limb if bitten, as there is no antidote for the bite of a Sicarius. Amazingly, there are reports of people keeping these spiders as terrarium pets on account of their non-aggressive disposition and their fascinating habit of throwing sand over themselves as a method of concealment. (Note to self: don't go walking around barefoot in the South African desert!)

sorry people the deadliest spider is the "sydney funnel web" spider,trust me i know,ive been up close and personal with them and i know not to mess with them.they have 18 deaths to there name scince records began in the 70,s but that death toll would have been alot more if it wasnt for the introduction of antivenom in 1980.they can kill a human in 15mins but dogs are immune.so the crown has to go to the "SYDNEY FUNNEL WEB" spider.