It come days after the 40-year-old BBC Radio 5 Live newsreader revealed on social media that she had only days to live.
Her family confirmed that she had died this morning shortly after 3am, the BBC said.
A post on Bland’s official Twitter account said: “Our beautiful, courageous Rachael died peacefully this morning surrounded by her close family.
“We are crushed but she would want me to thank everyone who took an interest in her story or sent messages of support. You’ll never know how much they meant to her. Steve and Freddie xxx.”
Bland was diagnosed with primary triple-negative breast cancer in November 2016 and had been documenting her journey on her blog Big C Little Me, which has the tag line “Putting the can in cancer”.
Her podcast, You, Me and the Big C, reached number one in the UK podcast charts after Bland made her announcement earlier this week.
The 40-year-old was married to husband Steve for four years. The couple had a two-year-old son Freddie and would have celebrated their fifth wedding anniversary on September 14.
In a tweet posted on Monday, the broadcaster wrote: “I’m told I’ve only got days. It’s very surreal.”
In an early episode of her podcast she told how she had discovered she had cancer after breastfeeding Freddie.
She said: “I had pain first. I had this weird soreness. It was kind of inside my armpit. It went away. It was just around the time I was breastfeeding.
“But because of that I was having a little bit of a feel. When I found it, I was like: ‘How did I miss this?’
“It was the size of a walnut.”
Originally from the Cardiff area, she had joined the BBC in 2001, and her career started at Radio Wiltshire, where she worked as a journalist and newsreader.
She later joined BBC Radio 5 Live where she became a feature on Richard Bacon’s late-night show and ended up staying on. She also began presenting on BBC News.
In 2011 when the BBC relocated to Salford, Bland’s was the first voice heard on Radio 5 Live’s first broadcast from the new location and studios.
Her husband Steve told the BBC: “Rachael’s death has left a huge hole in our perfect little family that we’ll never be able to fill.
“She was an incredibly talented broadcaster as well as a wonderful and much-loved daughter, sister, aunt, niece, wife and, most importantly to her, a mother to her precious little Freddie.
“We all take such huge comfort and pride from the amazing and tireless work she has done since her diagnosis to reduce the stigma around cancer and prove that it is possible to live life to the fullest even when facing huge challenges on a daily basis.
“At the end, even though her body was at its weakest, her voice was at its strongest and most powerful.
“Rachael was and will always be an incredible inspiration to everyone she met. To us, she was perfect in every way and we will miss her more than words can say.
“We just ask that everyone respects our family’s privacy as we try and come to terms with losing our beautiful girl.”
BBC Director-General Tony Hall said: “Rachael was a popular and inspiring journalist. Everyone has been moved by her courage and dignity.
“She will be hugely missed by her many listeners and by staff across the BBC. Our sympathies go out to her family and many friends at this difficult time.”