"I'm so excited to be hosting Together At Christmas here at Westminster Abbey," Kate said to the camera.
ITV released a first look at the festive special, Royal Carols: Together At Christmas, on Friday, which is due to air on Christmas Eve.
The Together At Christmas carol service was hosted and spearheaded by the Duchess, and supported by The Royal Foundation last week, to pay tribute to the incredible work of individuals and organisations across the UK who have supported their communities through the COVID-19 pandemic.
WATCH: Kate Middleton wears Christmas jumper as she hosts Christmas carol concert
The royal mum-of-three stunned in a red Catherine Walker dress and matching accessories for the service, but opted for a collared and rose-printed Miu Miu cardigan during a segment for the ITV special.
Miu Miu cashmere-jacquard cardigan, £1,350, Net-A-Porter
The event features carols sung by the Westminster Abbey choir alongside Leona Lewis and Ellie Goulding – who performed at the Cambridges' wedding reception in 2011.
The Cambridges at the concert
In a moving message written for the concert, the Duchess penned: "We have lost loved ones, seen our frontline workers placed under immeasurable pressure, and we have experienced heart-wrenching isolation from those we hold most dear.
"Alongside this, we have seen how communities have come together to support those most in need.
"And through our separation from others, we have been reminded just how powerful human connection is to us all.
"Just how much we need one another. And how loving and feeling a sense of belonging to one another can provide comfort in tough times. The importance of simply being together."
Royal Carols: Together At Christmas will air on Christmas Eve at 7:30pm on ITV and ITV Hub
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