The cancer campaigner and mother-of-two - who was diagnosed with incurable bowel cancer in 2016 - passed away peacefully on Tuesday 28 June surrounded by loved ones, her family has said in a statement.
Radio 1 DJ Roberts, who recently announced she had been declared cancer-free, said: "My heart hurts.
"Thank you for everything Deborah. Thank you for being so strong for so long and helping others when you were in so much pain yourself.
"You are the best of us. Thinking of your family and friends and I am forever grateful to you for helping me and my family."
Countryfile star Julia Bradbury, who is currently battling breast cancer wrote on social media: "Heartbroken that Dame Deborah James has died. She has been the most incredible ambassador of life & cancer campaigner. My thoughts are with her family & children. Such a huge loss. Your bright light will shine on Deborah."
Watch: Dame Deborah James has died at the age of 40
Lorraine Kelly tweeted: "We will be celebrating the life of our friend and force of nature @bowelbabe on todays show. We all knew it was coming but somehow I thought Deborah would bounce back like she always did. What a legacy she leaves us. Sending so much love to her family and everyone who knew her."
Prime Minister Boris Johnson released a statement in tribute saying: "I’m terribly saddened to hear that Dame Deborah James has died. What an inspiration she was to so many. The awareness she brought to bowel cancer and the research her campaigning has funded will be her enduring legacy. Because of her, many many lives will be saved."
Labour leader Keir Starmer said: "Deeply sad news. Dame Deborah James’ charity work was truly inspirational — even in the most challenging moments, she continued to raise awareness about bowel cancer and impacted so many people’s lives. Our thoughts are with her family and friends at this difficult time."
"Her legacy will live on. She will have saved so many lives with her inspirational attitude towards this horrendous disease. My live and thoughts are with her wonderful family. RIP Dame Debra, in pain no more."
Dame Deborah presented the BBC Radio 5 podcast You, Me & The Big C.
BBC Radio 5 Live Controller, Heidi Dawson said: "“As colleagues and friends, we are all heartbroken at Radio 5 Live. Our deepest condolences are with her family.
"Dame Deborah James was a naturally talented broadcaster, so funny, with a blunt honesty. She had the most incredible energy, a magnetism that drew you towards her.
"Deb – and the legacy she leaves behind – will forever be a treasured part of our station.”
BBC Director-General, Tim Davie added: "This is incredibly sad news. Dame Deborah James was a true inspiration. We’re so proud to have worked with her at the BBC. The way she talked about, and faced up to her cancer, moved the nation, inspired change and undoubtedly saved lives."
She announced in May she was stopping treatment and had moved into hospice care at her parents' home.
Dame Deborah recently set up the Bowel Babe fund in her name, which will support Cancer Research UK, The Institute of Cancer Research, The Royal Marsden hospital and promoting cancer awareness among younger people. It has now raised over £6.8 million.
Dame Deborah launched the BBC Radio 5 podcast You, Me & The Big C in 2018 with fellow cancer patients Lauren Mahon and Rachael Bland.