In a statement, her family paid tribute to "the most wonderful mother" and "cherished grandmother", whose "legacy of compassion and understanding will live on in her charities Childline and the Silverline, and through those of us who were lucky enough to love and be loved by her".

"We are grateful she is finally at rest with her beloved husband, Desmond Wilcox, but we will miss her immeasurably. She was our sunshine. We will always remember her endless capacity for joy, her ability to comfort every heartache, her beautiful way with words and her expert guidance in all things," said her three children.

Rantzen announced a diagnosis of stage four lung cancer in 2023, and became a vocal campaigner to change the law around assisted dying. In September 2026, she announced she had to abandon plans to end her life in Swiss clinic Dignitas, due to being too physically frail.

"Unfortunately, when I was strong enough to make the flight and go to Dignitas, my life was not unbearably painful; indeed, I was able to relax in my beloved cottage in the New Forest," she said in a statement. "And by the time life did become unbearable, I was too physically fragile to make the journey and go through the Dignitas process."

"So even though I had spent the money and made the plans, I was not ready to end my life back then, and did not realise that would be my last chance."

Rantzen was born in Berkhamsted, Hertfordshire, in 1940 and began her career in 1963 as a BBC radio studio manager. Having moved into television as a researcher, she became a presenter in 1968, as part of the consumer affairs show Braden's Week, before being appointed as the main host of its replacement programme, That's Life!, in 1973.

Part magazine, part consumer show, with hard-hitting investigations and jokes, That's Life! drew more than 20 million viewers at its peak – and ran for 21 years with Rantzen as anchor. After she successfully pitched an episode about child abuse to the then BBC controller Michael Grade, a set of phone lines was opened for 48 hours, which enabled children to call in and speak to social workers. The volume of responses led her to turn the service into a permanent fixture, launching the children's charity Childline in 1986.

In 1988, Rantzen created Hearts of Gold, a series profiling people responsible for outstanding acts of kindness, and hosted her own BBC Two chatshow, Esther, from 1994, when That's Life! came to an end, until 2002. Further TV projects included the consumer affairs show Old Dogs New Tricks, as well as competing in Strictly Come Dancing's second series and the 2008 edition of the ITV reality show I'm a Celebrity … Get Me Out of Here! She received an OBE for services to broadcasting, Bafta's Richard Dimbleby award for factual programming and a lifetime achievement prize at the Women in Film and Television awards.

Her wide-ranging charity work saw her act as a patron or vice-president of numerous organisations. In 2010, she launched the Silver Line – a free confidential helpline for older people, which led to her being made a dame for services to children and older people.

In 2010, she stood as an independent candidate for Luton South in that year's general election, coming fourth after winning 4.4% of the vote. She wrote numerous books, including a murder-mystery novel. In later years, she was a regular contributor to the One Show and hosted a podcast with her former That's Life! colleague Adrian Mills.

Her husband, Desmond Wilcox, whom she married in 1977, died in 2000. Rantzen is survived by their three children, Miriam, Rebecca and Joshua – as well as five grandchildren.