The 34-year-old Duke and the 37-year-old Duchess of Sussex arrived in Sydney on a Qantas Airways flight at 7 a.m., and the two were all smiles as they were flanked by a large crew of aides and officials.
The Duke and Duchess arrived at Syndey Airport shortly after 7am on Friday morning on a Quantas flight.
Admiralty House is the Sydney residence of the Australian Governor-General and hosts members of The Royal Family when they visit the country.
Admiralty House has also been used to host other global guests including US Presidents and the Pope.
They're expected to fly from Toronto to meet Prince Harry and Markle when the tour launches at the Sydney Opera House on Tuesday.
Their plans will be mixed with a little fun as Harry and Meghan will cuddle with koalas and joeys at the Taronga Zoo in Sydney before travelling to Tonga to have a dinner with King Tupou VI and Queen Nanasipau'u.
Their tour will take them to Dubbo in the NSW Central West, Melbourne and Queensland's Fraser Island.
They will be in Australia for a total of nine days, where they will open the Invictus Games in Sydney on October 20 and attend a number of other events including public picnics, farm visits and "Fluoro Day" for mental health.
The Daily Mail and The Sunday Times both report that Mulroney will be on hand with her husband, Ben, in an "unofficial capacity"-reportedly meaning they'll be paying their own way and kind of just casually tagging along on the royal tour, NBD".
And that's only day one! While their visit already seemed jam packed, there are plenty of chances to catch a glimpse of the royal pair.
We will have to wait and see if the couple get as involved in the dancing as Prince William and Kate did when they visited the tiny Pacific island of Tuvalu in 2012.