Charles III is only the second monarch to adorn Australian decimal currency.
His mother, Queen Elizabeth II, was crowned before Australia switched to dollars and cents in the 1960s.
The Royal Australian Mint released the first coin to have the king’s effigy, the $1 coin.
The first batch of 3.5 million coins have been delivered to banks and will start appearing in cash registers across the country.
The remaining denominations of circulating coins will be released throughout next year, based on bank demand.
Collector and investment coins bearing the king’s head are expected to go on sale early next year.
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Assistant Minister for Treasury Andrew Leigh said the coins’ release was a significant event for Australia.
“For most Australians, this will be the first time they have held in their hands a coin with a king. A lot of work has gone into producing these coins. Millions of people will be keen to get their own little piece of history.
“Under a tradition dating back to at least the 17th century, successive monarchs face in different directions on the coins. Queen Elizabeth II faced to the right. King Charles III now faces to the left.”
Coins bearing the late queen’s effigy would remain legal tender, the Royal Australian Mint confirmed.