The ABC has identified more than 1,000 Australian links in the data, which contains personal details including copies of the passports of hundreds of Australians.
In a statement, deputy tax commissioner Michael Cranston said the information included "some taxpayers who we have previously investigated, as well as a small number who disclosed their arrangements with us".
"It also includes a large number of taxpayers who haven't previously come forward, including high wealth individuals, and we are already taking action on those cases," he said.
The ATO said of the 800 Australian citizens found, 120 of them have been linked to an associate offshore service provider located in Hong Kong.
An ABC analysis has found 418 Australian individual passports in the documents linked to hundreds of companies through dozens of offshore service providers.
Mossack Fonseca uses offshore service providers, also known as "intermediaries" or "clients" to help incorporate companies.
These can be banks, law and accounting firms or individuals.
Mossack Fonseca says these intermediaries are the ones responsible for ensuring companies abide by the necessary laws.
The ABC has found many of the most popular clients used by Australians to incorporate companies through Mossack Fonseca are based in Hong Kong.
According to analysis by the ABC the client used most commonly by Australians is "Popular Corporate Service Limited", a little-known Hong Kong firm.
The ABC understands the ATO has part of the Panama Papers data, which it received from international law enforcement bodies.
Mr Cranston said the ATO has been analysing the data.
"We have been able to identify patterns such as clusters of individual taxpayer and advisers for further investigation," he said.
"The message is clear — taxpayers can't rely on these secret arrangements being kept secret and we will act on any information that is provided to us."
You can watch 'The Secrets of the Super Rich' on Four Corners on ABC TV at 8.30pm tonight.