Are there any cacti in Australia?

No, there are no cacti native to Australia. Cacti are ONLY native to North and South America, with the sole exception being Rhipsalis baccifera which is also native to Africa and Sri Lanka.

Whilst Australia doesn’t have any endemic species of Cacti, our favourable climate has resulted in several species becoming naturalised, meaning they have significant wild-distributed populations. The most common of these is the infamous Prickly Pear (Opuntia), which has infested every state and territory of Australia. The weed potential of the Prickly Pear cactus in Australia is so high that all species of opuntioid cacti except the Opuntia ficus-indica (Spineless Prickly Pear) have been declared Weeds of National Significance by the Australian Weeds Committee.

Native distribution of cacti:

Blue: Rhipsalis baccifera only

Green: All other cacti

Whilst Australia doesn’t have any native cacti, we do have a number of native succulent plants that are visually similar. The two most notable of which are: Lawrencia helmsii and Daviesia euphorbioides. Daviesia euphorbioides is a particularly interesting example because it’s name literally means “Euphorbia-like”. Euphorbia’s are a very large and diverse genus of succulents native to many parts of the world and are commonly confused and misidentified as cacti as they share many of the same traits, whilst having a completely seperate evolutionary histories.

So in summary, the closest native plant that Australia has to a cactus is the Daviesia euphorbioides - a succulent that looks like a Euphorbia, which in turn kind of looks like a cactus.