The Redback spider (Latrodectus hasseltii) is a potentially dangerous spider native to Australia. It resembles a Black widow spider. It is a member of the genus Latrodectus or the widow family of spiders, which are found throughout the world. The female is easily recognisable by its black body with prominent red stripe on its abdomen. Females have a body length of about a centimetre while the male is smaller, being only 3 to 4 millimetres long. The Redback spider is one of few animals which display sexual cannibalism while mating.
Redbacks are considered one of the most dangerous spiders in Australia. The Redback spider has a neurotoxic venom which is toxic to humans with bites causing severe pain. There is an antivenom for Redback bites which is commercially available.