But the Duke of Sussex is expected to return to the US shortly after the ceremony.
The Duke of Sussex has arrived at Westminster Abbey for his father King Charles III’s Coronation.
Prince Harry arrived at London’s Heathrow Airport on Friday, reportedly on a commercial flight from Los Angeles.
It’s thought it is the first time he has seen his family since his controversial memoir, Spare, came out.
But he will reportedly return to the US just hours after the ceremony, as it’s his son’s fourth birthday.
Prince Archie has remained in Los Angeles with his mother, the Duchess of Sussex.
A source told the US outlet Page Six that Harry intended to make “every effort to get back in time for Archie’s birthday”.
Prince Harry entered the abbey alongside his cousin Princess Eugenie.
He reportedly stayed at Frogmore Cottage on the grounds of Windsor Castle on Friday night – the residence he and Meghan were asked to vacate by the King.
Last month Buckingham Palace confirmed that Prince Harry would attend the ceremony alone.
However, officials have said Prince Harry and his uncle Prince Andrew will have no formal role in the ceremony, as they are not working members of the Royal Family.
Unlike other members of the family, he is not wearing robes or military uniform – despite the fact that he served in the army for a decade, including two tours of Afghanistan.
Relations between Prince Harry and other members of the family have been strained since his memoir was published.
The book vividly revealed fall-outs and disagreements with relatives, and he has since spoken of feeling “different” from the rest of his family.
The decision for Meghan to reject the invitation was widely seen as part of these continuing, unresolved family tensions.
And last month it was revealed that the King tried to stop Prince Harry taking legal action against newspapers over alleged phone-hacking.
In a witness statement revealed by court papers, Prince Harry said he was “summoned to Buckingham Palace” and told to drop the cases because of the effect on the family.