No, it is not legal to camp anywhere in Australia. Camping is allowed only in designated campgrounds and specific areas. Each state and territory in Australia has its own regulations and rules regarding camping. In some areas, you may find free camping spots or rest areas where camping is permitted, while in others, you might need to stay in developed campgrounds or national parks.
It is essential to research and follow the local regulations and obtain any necessary permits before camping. Camping in unauthorized areas can result in fines and penalties. Always practice responsible camping and follow the "Leave No Trace" principles to minimize your impact on the environment.