The 903kg (1990lb) haul of the drug, also called ice, is estimated to have a street value of A$898m (£546m; $680m), Justice Minister Michael Keenan said.
The drugs were concealed between floorboards in a shipment sent to Melbourne, according to the Australian Federal Police (AFP).
Two men have been charged with drug trafficking offences.
Prime Minister Malcolm Turnbull praised the police operation, describing drug traffickers as "merchants of death".
"This was nearly a tonne of ice, so this is a great credit to our border protection and our police in confiscating this enormous shipment," he said on Wednesday.
Authorities said the drugs probably originated in Asia, but they did not say where.
"You can see a fairly sophisticated concealment methodology where organised crime groups are going to great lengths to try and thwart the activities of law enforcement, particularly our border controls," AFP Assistant Commissioner Neil Gaughan said.
"But we are united in bringing these people to justice."
The arrested men, both from Melbourne, are aged 53 and 36.
In 2015, Australia's government established a national taskforce to tackle growing use of crystal methamphetamine.
The move followed a report by the Australian Crime Commission that found ice posed the highest risk to communities of any illegal substan