Scammers took advantage of the pandemic to fleece Australians of a record $851 million in 2020.
Investment scams accounted for about a third of total losses, with unsuspecting investors scammed $328 million.
Romance scams cost Australians another $131 million and payment redirection scams $128 million.
"Unfortunately scammers continue to become more sophisticated, and last year used the COVID-19 pandemic to scam and take advantage of people from all walks of life during this crisis," ACCC deputy chair Delia Rickard said.
Ms Rickard said that because many people did not tell the watchdog when they had fallen victim to a scammer, the real losses were probably even higher.
Victims lost an average of $7677 when they fell victim to a scammer, and people aged over 65 were the most likely to lose their money.
The boom in online transactions during lockdown also saw a rise in health and medical scams, which were 20 times higher than in 2019, accounting to $3.9 million in losses.
For the first time Victoria recorded the highest losses nationwide, with $49 million in losses, more than double the amount lost in 2019.
As people tried to ride out the state's repeated lockdowns with a new pet, or if they needed a second-hand car, scammers were there to take advantage.
"We saw scammers claiming the government restrictions meant people could not see items in person before purchase," Ms Rickard said.
Of course, despite the money paid, they never arrived.
Scams based on threats also increased by 178 per cent, to $11.8 million in losses.
Phishing activity, especially where scammers impersonated government departments, increased by 75 per cent, with 44,000 reports.
The consumer watchdog released its Targeting Scams report, which is based on more than 444,000 scam reports, on Monday.
Anyone who detects a scam, even if they are not a victim, can report it to Scamwatch.
Australian Associated Press