The trip is the couple's first Australian visit since the British monarch's coronation in May 2023.
They previously visited Australia in 2018 for the Gold Coast Commonwealth Games.
The Sydney Opera House sails will be lit up for the couple's arrival on Friday night before the royals are kept busy with formal dinners, wreath laying, fleet inspecting and hand-shaking during their five-day tour.
Members of the public will have multiple chances to glimpse Australia's new monarch as the royal couple visit iconic Sydney and Canberra landmarks while also making time for smaller community events.
The couple visited Australia for the Commonwealth Games in 2018 before the King's coronation. (Mark Metcalfe/AAP PHOTOS)
The Australian Monarchist League's Damien De Pyle said it would be a privilege for the nation to welcome the King back to Australia.
"It's obviously a very special country for him ... which is highlighted by the fact that this is the first Commonwealth country he's visited since becoming King," he told AAP.
The King and Queen will rest on Saturday, with official duties starting on Sunday, including a church service and a visit from Governor-General Sam Mostyn and NSW Governor Margaret Beazley.
The couple will travel to Canberra on Monday, where they will lay a wreath at the Australian War Memorial before receiving an official welcome at Parliament House.
The royals will also meet with Prime Minister Anthony Albanese and Opposition Leader Peter Dutton, plant a tree and tour the botanic gardens.
Fans will be able to see the pair about midday at the For Our Country memorial, which commemorates the military service of Aboriginal and Torres Strait Islanders.
Sydneysiders will be able to see the King and Queen at the Opera House on Tuesday about 4.30pm.
Mr De Pyle said the Australian Monarchist League would hand out flags at the Opera House and encouraged patriotic Australians to take the opportunity to meet the royals.
The couple will also visit the National Centre of Indigenous Excellence in Redfern and attend NSW Premier Chris Minns' community barbecue in Parramatta before embarking on a review of the Royal Australian Navy fleet.
The western Sydney event will promote the state's rich culinary and cultural diversity and allow the monarchs to meet outstanding citizens.
The King and Queen depart Australia on Wednesday morning.
It will be the first trip to Australia by a reigning monarch since 2011, when Queen Elizabeth II visited Brisbane, Melbourne, Canberra and Perth.
King Charles travelled to Australia 15 times before taking the throne.
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