Esther Rantzen is launching a new telephone counselling service for vulnerable elderly people.
Writing about her plans in the Daily Mail, the television presenter and one-time parliamentary candidate explained that she wanted the new charity to combat loneliness and the feeling "that if you ceased to exist no one would miss you".
She said the new telephone befriending service would be called "The Silver Line" and would be a point for older people to gain information, friendship and help with serious problems, as well as advice about organisations to contact as the next step.
It comes a quarter of a century after she established Childline, launched in the wake of a BBC programme about child abuse.
Ms Rantzen, 71, said: "Loneliness particularly strikes older people who are used to having a purpose in life, to being needed.
"Gradually, the community they used to belong to has shrunk away to nothing; children have moved out, bereavement or divorce means their partners have gone " .
She said that last year she realised there were parallels between the loneliness felt by suffering children and isolated old people.
"Old people, like children, can be neglected or abused by the people nearest to them: their family, their carers, the people upon whom they depend," she wrote. "All too often the elderly, like children, are terrified that if they ask for help, it will only make their lives even more painful."
She said the phoneline's name was "a positive title, not ageist in any way, not prescriptive".
The phoneline will be partly funded by private donations but will also operate as a charity. Ms Rantzen said she hoped it would be operating by the end of the year.