"The Duchess of Cambridge and I were inspired to see how the photographs have captured the resilience of the British people at such a challenging time.
"The Duchess of Cambridge and I send our best wishes and congratulations."
The chosen images - which focused on three themes, Helpers and Heroes, Your New Normal, and Acts of Kindness - include hospital staff at work, socially distanced birthday parties, lockdown haircuts, family visits through the pane of a window, protesters at Black Lives Matter marches and attending a funeral via Zoom.
The Countess of Wessex featured in one of the 31,000 portraits sent in to be considered for the online exhibition, but the only famous face to feature in the final 100 is Captain Sir Tom Moore, the former Army officer who raised tens of millions for charity in a lockdown fundraising initiative to mark his 100th birthday.
The final 100 images will feature in a digital exhibition from Monday, September 14 and a selection will also be shown in various locations throughout the UK over the coming months.
Catherine was joined on the judging panel by the National Portrait Gallery's director Nicholas Cullinan, writer and poet Lemn Sissay, photographer Maryam Wahid and Ruth May, the Chief Nursing Officer for England.
You can view the photos in the digital exhibition here.