The sad news, which comes just a month after the star's cancer diagnosis, was shared on the show's Facebook page, in a post that reads: "Such sad news- our friend and colleague Denise Robertson has lost her short but determined battle against cancer. Full tribute at 10.30.
"Please share your memories of her here. We are working on a special programme reflecting her work and achievements including many of your messages of condolence."
Denise shared her cancer diagnosis with fans in February, in an announcement that was also made on the 'This Morning' Facebook page.
"After almost thirty years of providing comfort to millions of 'This Morning' viewers, agony aunt Denise Robertson is in need of a lot of love herself today. Denise has told us she has pancreatic cancer," it said.
In the week that followed, Denise spoke to Holly Willoughby and Phillip Schofield live on air, thanking fans for their kind words.
Denise began appearing on ‘This Morning’ in 1988, and she also made guest appearances on shows including ‘Loose Women’ and ‘The Paul O’Grady Show’.