Chinese Australians
As a whole, Australian residents identifying themselves as having Chinese ancestry made up 5.6% of those nominating their ancestry at the 2016 census and numbered 1,213,903. At the 2016 census, 509,555 people declared that they were born in Mainland China, 86,886 declared that they were born in Hong Kong, while 46,882 declared that they were born in Taiwan. There are also a large number of persons of Chinese ancestry among those born in Southeast Asian countries such as Malaysia, Indonesia, Singapore, the Philippines and Vietnam.
Taiwanese Australians
Taiwanese people have only been counted on Australian censuses since 1976. Taiwanese people were originally classified exactly the same as Chinese people (so you could not easily tell who was Taiwanese), and Taiwan is still classified as a "subregion of China" in Australian censuses. In the 2016 Australian Census, 46,826 people indicated that they were born in Taiwan, but only 18,522 people indicated that they had Taiwanese ancestry. There are almost certainly more ethnically Taiwanese people in Australia than the amount that was born in Taiwan. There should be around 50,000–100,000 Taiwanese people in Australia in total. However, even getting an approximate number for the total Taiwanese people in Australia would be nigh impossible, due to the complicated political status of Taiwan, which ruins census data for Taiwan.