What is the least popular religion in Australia?

The least popular religion in Australia is often considered to be smaller, less mainstream faiths, such as Zoroastrianism or Jainism, which have very few adherents compared to major religions. According to the 2021 Census, a significant portion of the population identifies as having no religion, indicating a trend towards secularism. Among the recognized religions, those with the smallest followings typically include various indigenous beliefs and newer spiritual movements.