The Duke of Sussex speaking at Windsor Castle in Berkshire after the Duchess of Sussex gave birth to a baby boy (Picture: PA).
The Duchess of Sussex has given birth to a son, Buckingham Palace has announced.
The baby boy weighed 7lb 3oz and was born at 5.26am.
The Duke of Sussex was at his wife's side and mother and baby are both doing well, the palace said.
A beaming Harry said: "It's been the most amazing experience I could ever have possibly imagined.
"How any woman does what they do is beyond comprehension. But we're both absolutely thrilled.
"We're both absolutely thrilled and so grateful for all the love and support from everybody out there, it's been amazing, so we just wanted to share this with everybody."
Harry said the couple were "still thinking about names" for their son.
He said: "The baby was a little bit overdue so we've had a little bit of time to think about it.
"That's the next bit."
He said he planned to make another announcement in two days' time "so everyone can see the baby".
Harry and Meghan's baby is seventh in line to the throne, and the Queen and the Duke of Edinburgh's eighth great-grandchild.
The baby's gender was a surprise for the delighted couple, who chose not to find out what they were having.
The newest addition to the Windsor family is a first cousin of the Duke and Duchess of Cambridge's children, Prince George, Princess Charlotte and Prince Louis.
Ahead of the birth, Harry and Meghan made a personal decision to keep their arrangements private, amid speculation that they had opted for a home birth at Frogmore Cottage, close to the Queen's Windsor Castle residence.
They also said they would only share the news of the baby's arrival once they had had a chance to celebrate privately as a family.
Baby Sussex's birth comes less than a year after Harry married American former actress Meghan in a glittering ceremony in St George's Chapel, Windsor Castle.
Harry, 34, and Meghan, 37, became engaged following a whirlwind 16-month romance after going on a blind date in London.
The duke had told how "all the stars were aligned" when they met.
News they were expecting a baby was announced in October at the start of the couple's busy 16-day tour to Australia, New Zealand, Fiji and Tonga.
Harry branded the baby "our little bump", while Meghan said they "were nearly there" in the final weeks of her pregnancy.
Unless the Queen steps in at the last minute, the baby will not be an HRH or a prince due to rules limiting titles within the royal family which were introduced by King George V more than 100 years ago.