Attorney-General Christian Porter says the law needs updating after the boom in recent years of online companies trading in personal information.
Tech giants such as Google and Facebook will be forced to cough up far more cash if they breach privacy laws, under sweeping changes proposed to help protect the personal information of Australians.
Social media companies and online platforms that seriously or repeatedly breach privacy laws would be fined $10 million under the reforms, compared to the current penalty of $2.1 million.
Alternatively, they could be charged three times the value of any benefit obtained by misusing information or 10 per cent of their annual domestic turnover, depending on which figure is greatest.
For some companies, that could mean paying upwards of $100 million.
Online companies would also be required to stop using or disclosing personal information about individuals upon request, under the changes to be made through amendments to the Privacy Act.
Attorney-General Christian Porter says the act needs updating after the boom in recent years of online companies trading in personal information.
"We need better protections and stronger penalties and stronger incentives to ensure that the social media platforms do the right thing with our private information," he told reporters in Perth.
The current $2.1 million maximum penalty for breaching people's privacy is simply too low, he said.
"Frankly, with the level of profit these companies are making, that was almost irrelevant to them.
Under the proposed changes, the Australian Information Commissioner would also be given new powers to issue infringement notices for those who fail to cooperate with efforts to resolve minor data breaches.
Companies would be charged $63,000 and individuals could be fined $12,600.
The government also wants to give the commissioner more options to ensure breaches are addressed, including through reviews and publishing public statements about specific breaches.
The commissioner will also be provided with $25 million over three years to ramp up its investigations of privacy breaches.
Legislation to make the changes will be drafted ahead of community consultation in the second half of the year.
Opposition Leader Bill Shorten said protecting people's privacy is among a range of conversations lawmakers need to have with the biggest social media companies.
They also need to better regulate hate speech, he said, particularly after a video of the Christchurch massacre taking place was livestreamed.
"Social media is a fantastic development, the internet is fantastic, absolutely, but we can't allow it to become a swamp of hatred," Mr Shorten told reporters in Melbourne.
Prime Minister Scott Morrison, Communications Minister Mitch Fifield and Mr Porter will meet with executives from the biggest social media companies in Brisbane on Tuesday to discuss the uploading of videos of violent offending on platforms such as Facebook and YouTube.