Prince Harry wore a morning suit and medals at the ceremony and he sat with his cousin Princess Eugenie and her husband Jack Brooksbank in the third row, along with his uncle the Duke of York, Prince Andrew.
The Duke of Sussex has attended his father’s Coronation, sitting two rows behind his brother the Prince of Wales at Westminster Abbey.
The prince arrived alone without his wife Meghan, who stayed in the US, and he left immediately afterwards.
The BBC understands he was not invited to appear on the balcony at Buckingham Palace to greet the crowds following the ceremony.
It is thought he has since headed to Heathrow airport.It is the first time the prince has been seen at a public event with his family since his controversial memoir, Spare, was published.
Prince Harry got into a car alone shortly after the service had finished.
Hours later, on the Buckingham Palace balcony, the King and Queen were joined by other working members of the Royal Family, including the Prince and Princess of Wales, and their children.
Prince Harry’s wife, the Duchess of Sussex, remained in Los Angeles with their children, where their son Prince Archie is celebrating his fourth birthday.
A source earlier told the US outlet Page Six that Prince Harry intended to make “every effort to get back in time for Archie’s birthday”.
Prince Harry wore a morning suit and medals at the ceremony and he sat with his cousin Princess Eugenie and her husband Jack Brooksbank in the third row, along with his uncle the Duke of York, Prince Andrew.
Two rows ahead in the front were the Prince and Princess of Wales and their children Princess Charlotte and Prince Louis, as well as the Duke and Duchess of Edinburgh.
For the late Queen Elizabeth’s funeral last year, Prince Harry was in the second row – directly behind the King – at the abbey.