Arriving at Parliament House in Canberra on Thursday afternoon, William and Kate attended a reception hosted by prime minister Tony Abbott in the Great Hall.
Duchess Kate, 32, turned heads in an emerald green Catherine Walker coat dress which she paired with her favourite L.K. Bennett nude sledge pumps. The mother-of-one, who had left baby Prince George at home in the safe hands of his nanny, kept her brunette locks perfectly loose over her shoulders.
But it was William's speech that he delivered to the large audience that melted the Australians' hearts.
"There is so much to admire about Australia," William said, before giving special mention to the couple's visit to Uluru and Taronga Zoo, where Prince George met a bilby named after himself.
"Reluctantly, Catherine, George and I leave Australia tomorrow. Thank you for the warmth and generosity that has been shown to us during our visit. We go away with wonderful memories, and George goes away with his cuddly wombat which he has taken to chewing so lovingly.
"We greatly look forward to coming back and when we return, it will be to marvel again at all that Australia is and yet to become. Thank you."
The crowded room then broke into applause and the attention turned to the musician playing traditional music on a guitar.
The royal couple and the Australian politician chatted afterwards and looked like they had much to talk about since they last saw each other just before Easter. In those few days that had passed, William and Kate had travelled around the country, celebrating Easter in Sydney and spending a night glamping in Ayer's Rock among other visits.
See the pics: Kate exudes elegance in Australian Outback
The couple's tight schedule meant that William and Kate stayed for just over an hour before they were whisked off to their next, and third, engagement of the day at the National Portrait Gallery in Canberra. The visit to the art museum will no doubt resonate with the Duchess who is a patron of the gallery's equivalent in London.
Later in the day, William and Kate will also attend an evening reception at Government House, hosted by governor-general Dame Quentin Bryce in their honour.