“The Queen, The Duke of Edinburgh, The Prince of Wales, The Duchess of Cornwall, The Duke and Duchess of Cambridge, Lady Jane Fellowes, Lady Sarah McCorquodale and Earl Spencer have been informed and are delighted with the news,” read the Twitter statement.
“The Duchess’ mother, Doria Ragland, who is overjoyed by the arrival of her first grandchild, is with Their Royal Highnesses at Frogmore Cottage.”
Princess Beatrice and Eugenie’s father, Prince Andrew, the Duke of York, also shared Meghan and Harry’s birth announcement, along with the caption, “Congratulations to The Duke and Duchess of Sussex on the safe delivery of your baby boy!”
Charles Spencer — brother of Diana, Princess of Wales and uncle to Harry — tweeted his congratulations.
He wrote: “Really very lovely news today — many, many, congratulations!”
Meghan’s estranged father, Thomas Markle, also released a statement via The Sun.
“I’m delighted to hear that mother and child are doing well,” he wrote in a statement.
“I am proud that my new grandson is born into the British royal family and I am sure that he will grow up to serve the crown and the people of Britain with grace, dignity, and honour.
“GOD bless the child and I wish him health and happiness, and my congratulations to my lovely daughter Duchess Meghan and Prince Harry, and GOD save the Queen.”
Some of Meghan’s former Suits co-stars also offered their congratulations, including Sarah Rafferty.
British Prime Minister Theresa May was also quick to congratulate the royal couple.
Here are some of the other celeb reactions: