An effigy of the King, released on Thursday by the Royal Australian Mint, will start circulating before Christmas.
The first coin to bear the effigy will be the dollar, with other denominations to be rolled out progressively in 2024, based on demand from banks.
The image of King Charles III is the official Commonwealth effigy and was designed by the Royal Mint in London and given royal approval.
In line with tradition, King Charles will appear on coins facing left, in an about-face from the reign of the late Queen Elizabeth II who faced right.
Royal Australian Mint chief executive Leigh Gordon said the question of when the King will be seen on Australian coins had been a frequent one since the Queen's death.
"As Australia's circulating coin manufacturer, we appreciate the importance of the transition, and we are applying our considerable skill and expertise producing Australia's coins bearing the new royal effigy," he said.
"The staff at the mint have been very deliberate and measured in the steps to date and we are now well positioned to expand into production."
Assistant Treasury Minister Andrew Leigh said for many Australians it would be the first time they've seen a different face on the currency.
"For seven decades, Australians have seen a Queen on their coins. Every decimal currency coin has featured Queen Elizabeth II," he said.
"Now, for the first time since 1953, the King's effigy will appear on an Australian coin.Â
"For most Australians, this will be the first time they have held in their hands a coin with a King."
Collectible coins bearing King Charles III will be on sale from early next year.
All coins carrying the image of Queen Elizabeth will still be able to be used as legal currency.