Her attendance at the events in London are the first time that Catherine, who is widely known as Kate, will be at a major royal occasion since ending chemotherapy.
Buckingham Palace's announcement came as her husband Prince William described the past year in which both Kate and his father battled cancer as "brutal" and probably the "hardest" of his life, said AFP.
Charles, 75, will lead the royal family at two of the most important events in the royal calendar -- Saturday evening's Festival of Remembrance commemorative concert and Sunday's ceremony at the Cenotaph war memorial.
Senior royals traditionally attend the solemn wreath-laying at the monument near parliament alongside political leaders, current and former members of the armed forces, including war veterans.
But the presence of Charles's wife Queen Camilla, 77, has not yet been confirmed after she withdrew from engagements earlier this week due to a chest infection.
Her attendance would be subject to medical advice nearer the time, the palace said.
William, 42, on Thursday revealed how he had coped since both illnesses were announced.
"Honestly, it's been dreadful. It's probably been the hardest year in my life," he told reporters at the end of a four-day visit to South Africa for his Earthshot prize initiative.
"So, trying to get through everything else and keep everything on track has been really difficult."
The palace in February announced that Charles had been diagnosed with an undisclosed cancer and would withdraw from public life to undergo treatment.
The following month Kate, also 42, revealed that she too had been diagnosed with cancer and was undergoing chemotherapy.
Both have since made limited returns to public duties, although head of state Charles, who recently toured Australia and Samoa, is still undergoing treatment.
'Crack on'
Catherine said in September that she had completed her chemotherapy and was looking forward to undertaking more engagements "when I can".
"I'm so proud of my wife, I'm proud of my father, for handling the things that they have done," William added.
"But from a personal family point of view, it's been, yeah, it's been brutal," he said.
This year's awards ceremony for William's Earthshot prize was held in Cape Town on Wednesday.
The initiative honors projects seeking novel solutions to the challenges facing the world's nature and climate.
William is also committed to a five-year program, Homewards, launched by his philanthropic foundation to tackle homelessness in the UK.
When told he appeared relaxed, William said he "couldn't be less relaxed this year".
"It's more a case of just crack on and you've got to keep going," he said.
"I enjoy my work and I enjoy pacing myself, and keeping sure that I have got time for my family too," he added.
He and Kate have three children together: Prince George, 11, Princess Charlotte, nine, and six-year-old Prince Louis.
In addition to health problems, the royal family has this year faced continuing tensions surrounding William's estranged brother Harry.
Harry's ties with his family have been increasingly fraught since he and wife Meghan quit royal life and moved to California in 2020.
William and Harry used to be close -- a bond that was forged with the death of their mother Princess Diana in 1997. But according to British media reports, they have not spoken to each other in two years.
