It will span 16 days and also includes visits to Fiji, Tonga and New Zealand.
The Duke and Duchess of Sussex have kicked off their 16-day-tour of Australia and received a toy kangaroo for their unborn child.
Cameron Kerr, the director and chief executive of Taronga Conservation Society Australia, welcomed the couple to Cammeraygal land, while Lille Madden, a 23-year-old traditional owner from the Gadigal people, said the welcome to country on behalf of local elder Dennis Foley.
Harry, who is Queen Elizabeth II's grandson, married Markle on May 19 at Windsor Castle.
It's been quite a whirlwind year for Meghan and Harry - in less than one year, they got engaged, tied the knot AND found out she's pregnant!
The Kingdom Choir gospel singers who performed Stand By Me at Harry and Meghan's wedding sent their best wishes to "the handsome couple".
The couple made the announcement after they touched down in Australia this morning.
"Wishing them all the best", May wrote in a tweet.
Banksy prank 'a coup on the art world'
Sotheby's said the painting has now been retitled "Love is in the Bin" and authenticated by Banksy's Pest Control agency. Last week's self-destruction was the latest in a long history of anti-establishment statements by the street artist.
The couple spent a few minutes talking to Mrs Dunne, who at one point put her hand on the Prince's face, before his wife Meghan leaned in to kiss Mrs Dunne.
Several of the representatives congratulated the couple on their baby news.
Meghan chose the fitted shift dress as she stepped out in public for the first time since the news of her pregnancy was revealed.
The couple had a meeting with the Governor-General Sir Peter Cosgrove and his wife Lynn, Lady Cosgrove during their first engagement of the day. The royal baby will become the seventh in line to the British crown. "They didn't get to enjoy married life just as a couple for too long, but it'll be gorgeous with a child".
WATCH: 9Honey meets some of the royal fans gathered outside the Opera House for a chance to meet Harry and Meghan.
Tuesday marks their first public appearance since announcing the news.
Prince Harry leaned down, expecting to be gifted his own bunch, but Dasha did not look thrilled with the prospect.
Even though working royal family members can't participate in social media, Kensington Palace does have its own social media accounts to share official announcements and photos.