The Duke and Duchess of Sussex are expecting their first child next spring.
The announcement from Kensington Palace comes as Meghan and Prince Harry arrived in Sydney on Monday ahead of a 16-day tour of Australia, New Zealand, Fiji and Tonga.
The couple are said to be “delighted” to share the happy news with the public.
The baby will be seventh in line to the throne.
The Queen and senior royals were told about the pregnancy as they gathered in Windsor for Princess Eugenie’s wedding last week.
Meghan wore a long, dark blue coat, sparking ‘baby’ speculation, which has now been confirmed.
It is their first official royal tour since their wedding five months ago, also at St George’s Chapel, Windsor.
Prime Minister Theresa May has sent congratulations to the couple.
“My warmest congratulations to the Duke and Duchess of Sussex on the happy news they are expecting a baby in the spring, wishing them all the best,” she said.
No changes to the itinerary are expected.
The baby will be a first cousin to Prince George, Princess Charlotte and Prince Louis but will not be a prince or princess unless the Queen steps in ahead of the birth.