Some of the spiders in Australia are venomous and thus dangerous.
Here is a list of some of the common spiders you will find in Victoria and

Red-back Spider
As the spider rarely leaves its web, humans are not likely to be bitten unless some part of the body (eg. the hand) is put into the web. Always check before moving items that have been stored outdoors for some time. The bite is highly poisonous and immediate medical attention is required.
White Tailed Spider
Bite is mildly poisonous but the white tailed spider has been suggested as a culprit in rare cases of large scale necrotic lesions but there is little supporting evidence, due to this possibility it is essential to seek medical attention immediately.
Brown House Spider
The Brown House spider (sometimes known as the Cupboard spider) is often found indoors in dark places, inside or under furniture. Mildly poisonous bite.
Black House Spider
The black house spider is a timid spider and will normally only venture from its retreat when prey is entangled in the web. Mildly poisonous bite.
Wolf Spider
When disturbed they rapidly run across the ground. When they stop suddenly their colour patterns can make them difficult to see. Mildly poisonous and no records of serious symptoms.
Jumping Spider
The common name comes from the habit of these spiders of jumping on their prey, which they locate with the large pair of eyes. They can jump up to a distance of several centimetres. Timid with a low poisonous bite.
Daddy Long-Leg Spider
Relatively harmless, old wife’s tales will have you believe that these spiders are extremely venomous which is actually untrue.
Garden Orb-Weaving Spider
The spider rests upside down in the centre of the web. At dawn the web is often taken down and the spider then rests on nearby foliage. Mildly poisonous bite.
Huntsman Spider
In the bush they can be found sheltering during the day beneath the loose bark of eucalyptus. Timid spider with a low poisonous bite.
St. Andrews Cross Spider
The silken cross may be used for strengthening the web, for camouflage or for enhancing prey catches. Bite is considered harmless.
Badge (Huntsman) Spider
Outside it can be found hunting for prey on tree trunks or foliage, during the day they will retreat beneath the bark of a tree for safety.