The previous record was 314.5t in 1997.
The record was achieved despite a slow start in the March quarter, when production was only 74t due to wet weather and production problems at some operations.
Surbiton director Dr Sandra Close said 2018's production was worth A$17.3 billion at the average spot price.
Gold production totalled 81t in the December 2018 quarter, making it the third consecutive quarter where output exceeded 80t.
"It took 21 years to break the old calendar year record and the outlook for the near term looks positive but of course there can always be surprises," Close said.
"Following a fall to just 220t in calendar 2008, the industry has bounced back, helped in part by the weakening of the Australian dollar against the US dollar, as it has fallen from around parity to near US70c in the last decade."
Close noted the Australian dollar gold price had also reached a new record of A$1876 an ounce last month, up from an average $1711/oz in the December quarter.
Production additions this year will come from Gold Fields and Gold Road Resources' new 300,000oz per annum Gruyere mine in Western Australia, while Kirkland Lake Gold's Fosterville mine in Victoria is poised for a record year of around 600,000oz of gold production this year.
The top five largest producers shifted over the course of the year.
Newcrest Mining's Cadia operation in New South Wales took the crown as 2018's largest producer, dethroning Newmont Mining's Boddington operation in WA.
Cadia produced just over 750,000oz while Boddington produced 710,000oz.
Newmont and Barrick Gold's Super Pit was second last year, but dropped to third.
Newmont's Tanami in the Northern Territory was fourth with 496,000oz produced, while AngloGold Ashanti and Independence Group's Tropicana mine in WA was fifth with production of 477,908oz.
"Super Pit output fell to just under 630,000oz for 2018, following the pit wall failure in May," Close said.
"It dropped out of the list of the [December] quarter's top five gold producers for the first time since Surbiton began its quarterly gold survey over 25 years ago."
The top five producers for the quarter were Cadia, Boddington, Tanami, Tropicana and Fosterville.