More than 30 members of the royal family are set to gather at the BBC’s Platinum Party at the Palace on the third night of the Jubilee celebrations.
The Queen also won't be in attendance after she missed the third day of festivities including the Epsom Derby on Saturday, but watched on television from home.
Among the royal attendees attending the live concert will be the Prince of Wales, the Duchess of Cornwall and the Duke and Duchess of Cambridge.
But Harry and Meghan, whose daughter Lilibet is celebrating her first birthday, will not be among those in the royal box.
A spokesperson for the couple, who stepped down as senior royals in 2020, said they were spending the day privately.
Thousands gathered on The Mall on Saturday evening ready for the grand show which will see performances by a host of stars including Queen, Diana Ross, Alicia Keys, Duran Duran and Nile Rodgers.
On Friday, Harry and Meghan made their first public appearance alongside the Windsors since they stepped down as senior royals two years ago.
'This is going to be a night to remember', says ITV News Royal Editor Chris Ship live from The Mall
They joined scores of family members at the special Jubilee service of thanksgiving in St Paul’s Cathedral, but sat far across the aisle from Charles, William and Kate.
They also missed a Guildhall reception for the royals afterwards.
William and Kate shared a "sneak peak" of the preparations for Saturday's concert in a Twitter video, following a surprise visit to Cardiff with Prince George and Princess Charlotte.
Others expected to be out in force are the Earl and Countess of Wessex and their children Lady Louise Windsor and Viscount Severn, the Princess Royal and Vice Admiral Sir Tim Laurence, Princess Beatrice and her husband Edoardo Mapelli Mozzi, and Princess Eugenie and her husband Jack Brooksbank.
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Anne’s son Peter Phillips is expected to be joined by his children Savannah and Isla, while Zara and Mike Tindall, who spent the day at the Epsom Derby with Anne and Sir Tim, will also be there.
The Queen’s cousins – the Duke of Gloucester, the Duke of Kent and Prince Michael of Kent – with the Duchess of Gloucester and Princess Michael of Kent – and Princess Margaret’s daughter Lady Sarah Chatto and her family are due to attend, along with a number of other extended family members.