The King will lay the first wreath on behalf of the UK at the Cenotaph. He will be followed by Prince William and Princess Anne, then Prime Minister Sir Keir Starmer and the country’s other political leaders.
Services will be held in almost every town and city across the UK – with some of the biggest gatherings expected in Belfast, Edinburgh, Cardiff, Plymouth, Liverpool and Manchester.
In Belfast, Northern Ireland’s First Minister Michelle O’Neill is due to take part in the official ceremony, making her the first senior Sinn Féin figure to do so.
Several Sinn Féin politicians have laid wreaths at the Cenotaph in Belfast in previous years, but they have not attended the main Sunday ceremony.
King Charles, the Prince and Princess of Wales and other senior royals also attended the Festival of Remembrance event at the Royal Albert Hall on Saturday night.
It was Catherine’s first major formal appearance since finishing chemotherapy.
She is gradually returning to public duties following her cancer treatment earlier this year.
The King, who has also been treated for cancer, received a standing ovation from the audience when he arrived.
