The Princess of Wales is hosting her annual festive musical service at the iconic London venue, with a congregation comprising dignitaries, stars, and everyday helpers who have supported their local areas.
The sizable congregation will enjoy a mix of traditional hymns, orchestral pieces, and literary excerpts from stars like award-winning actors.
The central message of the service, held in the candle-lit Abbey on the afternoon, is kindness and showing love to others.
Attending the event are Jonathan and Anna Cordiner, whose child passed away from a brain tumour, and who established a foundation, a support fund, to help households where there is a terminally ill child.
"The dedication, empathy, and kindness you show, often discreetly and without words, and without any expectation or recognition, make an profound impact to the circumstances of individuals," the Princess expressed in a letter ahead of the festive gathering.
The Princess of Wales is continuing her own steady comeback to the public eye following her health challenges and treatment, last month delivering her major oration since 2023, in which she talked about recognising the "selfless, commonly overlooked efforts of carers".
Those coming to the Abbey will enjoy performances from budding artists backed by the Future Talent charity, established in part by the Duchess of Kent to widen access to instrumental training.
Trumpeter Carys Wood, 18, who performs on the trumpet and is from southwest Wales, has been helped by the organisation, with funding assisting with instruments, tuition, and transportation expenses - and she said it was "amazing" to be performing at the evening's event.
"Pursuing music is often costly," she stated. She is now a student at the prestigious music academy, and added that "each individual ought to be given the possibility" to hone their artistic talents.
Eliza, Carys's sister who is 11, who is a euphonium player, will be present at the Abbey. "It's unbelievable that I get to perform here in front of so many notable figures," she said.
Within the audience will be people from various age groups.
That will feature nine-year-old Saphia Turner, recipient of a prize for youthful altruism, who produces drawings and undertakes charity feats to raise money for food banks.
The Abbey has been adorned with custom-created holiday decorations, with well-known chef Mary Berry and flower expert Simon Lycett contributing to their design.
The musical lineup includes singer Katie Melua, choristers from Westminster Abbey and a nautical singing ensemble, the group Fisherman's Friends, who said the invitation to sing was "the perfect culmination."
The Together at Christmas carol concert will be aired by a major network on Christmas Eve.