Catherine, Princess of Wales, is presiding over her annual Christmas carol concert at the iconic London venue, with a congregation comprising members of the royal family, famous faces, and community champions who have supported their local areas.
The sizable congregation will enjoy a mix of festive songs, musical performances, and spoken word pieces from actors such as Chiwetel Ejiofor and Kate Winslet.
The focus of the service, held in the candle-lit Abbey on Friday, is generosity and expressing affection towards one's neighbour.
In the audience are Anna and Jonathan Cordiner, whose child passed away from a tumour, and who set up a charity, a charity called Kayleigh's Wee Stars, to support families who have a youngster facing a life-limiting condition.
"The time, care and compassion you give, often quietly and unspoken, and without any hope for reward or acknowledgement, make an remarkable change to the well-being of people," Her Royal Highness stated in a message before the carol service.
The princess has been making her own measured re-emergence to official duties after her cancer diagnosis and chemotherapy, last month delivering her first public speech for two years, in which she reflected on recognising the "discreet, frequently unseen labour of caregivers".
Guests arriving at the Abbey can listen to talented youth performers backed by the Future Talent organisation, co-founded by the Duchess of Kent to broaden opportunities for instrumental training.
Trumpeter Carys Wood, 18, who performs on the trumpet and is from Pembrokeshire, has been assisted by the charity, with grants helping towards musical instruments, lessons and travel costs - and she said it was "amazing" to be performing at the evening's event.
"Musical pursuits are frequently pricey," the musician remarked. She is now studying at the prestigious music academy, and added that "each individual ought to be given the possibility" to develop their musical skills.
Eliza, Carys's sister who is 11, who plays the euphonium, will be present at the Abbey. "I never imagined I would perform in front of so many important people," she said.
Among the guests will be individuals spanning multiple eras.
That will include Saphia Turner, aged nine, honouree of a youth community award, who creates and sells art and completes fundraising tasks to raise money for food banks.
The Abbey has been decorated with custom-created holiday decorations, with well-known chef Mary Berry and flower expert Simon Lycett contributing to their design.
Among the musical performers will be Katie Melua, the Westminster Abbey choristers and a maritime folk band from Cornwall, the Fisherman's Friends, who said the chance to take part was "the icing on the cake for us."
The festive event titled 'Together at Christmas' will be broadcast on a major network on Christmas Eve.
Elara Vance is a Dutch market analyst and lifestyle blogger who specializes in curating premium products and sharing insights on sustainable shopping trends.