Australia's population has doubled over the last 50 years, data from the national census revealed on Tuesday.

The Australian Bureau of Statistics (ABS) published the results of the 2021 census, which was conducted on August 10 last year.

It found that 25,422,788 people were living in Australia at the time of the census, an increase of 8.6 percent since the 2016 census and about 103.4 percent from 12,493,001 counted in the 1971 census.

More than 1 million residents migrated to Australia from overseas between 2017 and 2021, with more than 20 percent coming from India.

More than 50 percent of Australian residents in 2021 were either born overseas or had at least one parent born overseas.

The number of Australians who reported speaking a language other than English at home increased by about 800,000 from 2016 to over 5.5 million.

Mandarin continues to be the most common language other than English used at home, with 685,274 reporting using it at home.

There were 812,728 people in Australia identified as Indigenous in 2021, an increase of more than 25 percent from 2016.

More than 8 million people reported suffering from long-term health conditions, with mental health problems, arthritis, and asthma is the most common.

Statistician David Gruen said it was the first time the census has collected health data.

"This is critical data to inform planning and service delivery decisions about how treatment and care are provided for all Australians," he said in a statement.

"Census data complements existing ABS health surveys by providing additional insights about the communities that require services to support complex health needs." (AA/IANS)