"While these funds were repaid in full, it is clear that the banks benefited enormously from public financing when private funds were unavailable," wrote David Macdonald, author of the report released Monday.
"In addition, had the rapid and enormous deployment of public funds not been available, most, if not all, Canadian banks would have encountered serious difficulty."
The left-leaning think-tank estimated the country's largest financial institutions borrowed nearly $75 billion in short-term collateralized loans from the Bank of Canada and the U.S. Federal Reserve, peaking at $41 billion and $33 billion respectively.
The banks also sold a total of some $69 billion worth of insured mortgage-backed securities to the government, the report estimated.
The Centre for Policy Alternatives based its report on information provided by Canadian public institutions and analysis of the banks' financial reports.
The report noted that much of its work was based on estimates because the federal government and the Bank of Canada have refused requests for a detailed accounting.
"A healthy financial system cannot be based on massive government support for which the details remain secret," the report said.
"It is only through an honest and transparent examination of what occurred and how it can avoided in the future that a stronger financial system can be built, which is in everyone's best interest."
Ottawa has said repeatedly that Canada has one of the soundest banking sectors in the world and the country's banks did not require a bailout during the 2008-09 financial crisis.
However, the banks did receive help from Bank of Canada programs to make borrowing money easier and CMHC's insured mortgage purchase program that helped the banks raise cash.
Finance Department spokesman Chisholm Pothier said the government extended financing to the Canadian banks, not subsidies, to allow them to continue to provide credit to businesses and consumers during the crisis.
"The credit was extended at competitive interest rates to protect taxpayers. Financial institutions accepting this credit paid interest on the loans," Pothier said.
"Not only did these measures play an important role in supporting Canadian business during the credit crunch, they also made money for Canadian taxpayers."
In the U.S., Congress authorized US$700 billion for the bailout of financial companies and automakers during the financial crisis under its Troubled Asset Relief Program, or TARP.
A report last week found that the U.S. government is still owed US$118.5 billion including US$14 billion that has been written off or otherwise lost.