The images, which will feature in an exhibition of 75 photographs depicting Holocaust survivors with their family members, were released to coincide with Holocaust Memorial Day on Monday.
The duchess, who is a patron of the Royal Photographic Society, described the survivors she photographed as "two of the most life-affirming people" she had ever met.
Speaking about their stories, she said in a press statement: "It is vital that their memories are preserved and passed on to future generations, so that what they went through will never be forgotten."
One of her portraits, which were inspired by the Dutch artist Johannes Vermeer, shows Steven Frank, who survived multiple concentration camps. Originally from Amsterdam, he and his two brothers were three of only 93 children to survive the Theresienstadt camp -- from the 15,000 sent there.
He is photographed along with his granddaughters Maggie and Trixie Fleet, aged 15 and 13.
The other picture taken by the duchess is of Yvonne Bernstein, who, as a small child, spent much of the Holocaust in hiding in France.
She appears along with her 11-year-old granddaughter Chloe Wright.
To make the portraits more personal, Frank and Bernstein were photographed with items of family significance.
Frank brought a pan his mother used throughout their time in the concentration camps, as well as a tomato from his garden. As a young boy in Theresienstadt camp, he helped another prisoner by watering his tomatoes.
Speaking about this, Frank said: "Since the war I have grown tomatoes at home in the greenhouse and every time I water them I think of this man -- I don't even know his name. I still feel 75 years on that I'm watering his tomato plants for him."