Kensington Palace confirmed the exciting news on social media, writing: "Their Royal Highnesses The Duke and Duchess of Sussex are very pleased to announce that The Duchess of Sussex is expecting a baby in the Spring of 2019.
"Their Royal Highnesses have appreciated all of the support they have received from people around the world since their wedding in May and are delighted to be able to share this happy news with the public."
Meghan Markle sparked rumours she was pregnant earlier this week when she stepped out in a loose-fitting Givenchy coat at Princess Eugenie's wedding.
Off the back of her appearance, Twitter lit up with speculation that she was expecting.
Earlier today, the Duke and Duchess of Sussex touched down in Sydney ahead of their royal tour which commences tomorrow.
Their itinerary for Tuesday includes an official welcome by Governor-General Peter Cosgrove at Admiralty House, where they'll meet athletes competing in Sydney’s Invictus Games.
While in Australia, the pair will also visit Sydney's iconic Taronga Zoo and the Opera House, where they "will have an opportunity to meet members of the public".
The royal will also visit Dubbo, Melbourne and Fraser Island before they head to New Zealand, Tonga, and Fiji as part of their tour.