The Australian Government legalized CBD oil for medical purposes back in 2016. CBD oil derived from industrial fiber hemp is legal in Australia while cannabis oil derived from the marijuana plant with high THC level is illegal. At the moment limited number of Australians are legally using CBD oil to treat various medical conditions. At the moment it is not possible to buy CBD oil over the counter in Australia.
You can also import CBD oil in Australia, but there are requirements that the product must not include words like cannabis or marijuana. CBD oil must also not include any images of the marijuana plant other than the seed. Imported CBD oil must not make any health claims or nutrition content claims about cannabidiol. Lastly, the product must not claim that it produces a psychoactive effect.