Mooney was born in Broadgreen Hospital to Gladys (née Norbury) and Edward Mooney. She spent her earliest years in Liverpool on a council estate called The Green on Queen's Drive. She passed her eleven plus and went to Aigburth Vale Girls' High School (merged with another school to become Calderstones School in 1989). Mooney moved to Wiltshire at the age of fourteen, when her parents bought their first house. She then attended school in Trowbridge, Wiltshire, at Trowbridge Girls' High School (a girls' grammar school which merged with a boys' grammar school to become the comprehensive The John of Gaunt School in 1974). She passed eight O levels and took English, Latin and Art at A level. She applied unsuccessfully to the University of Oxford (at that time nobody from her school had been admitted to Oxford), and went on to study English Language and Literature at University College London, where she obtained a distinguished First in 1969. She met philosophy student Jonathan Dimbleby while they were both working on the student newspaper Pi. Dimbleby became her first husband; they married in February 1968 in Kensington after knowing each other for four months.
Giving up her idea of postgraduate work, Mooney became a journalist in 1969, contributing first to the Bath Chronicle and the Times Educational Supplement (whilst teaching part-time in Bath) then got her first job on Nova Magazine as Assistant to the Editor. In the early 1970s, Mooney wrote for the New Statesman, the Daily Telegraph Magazine, Cosmopolitan and many others. From 1979–80 she was a columnist on the Daily Mirror. She has also been a regular columnist for The Times (2005–07), The Sunday Times (1982–83) and The Listener (1984–86). From 1970 to 1979 she was a freelance journalist. (Her reference to Margaret Thatcher in Nova magazine in 1973 as a 'possible future Prime Minister' is believed to have been the first suggestion of its kind in the media.) In January 1976 she wrote a deeply personal article for the Guardian newspaper about the experience of having a stillborn child. This article was to have far-reaching effects as it was the first time a journalist had written on the subject with such raw feeling, and it directly inspired a shift in the awareness of how to treat stillbirth as well as the foundation of the Stillbirth Society, later to be known as SANDS. As well as her fiction (see below) Mooney has written many other books, including 'Bel Mooney's Somerset' (1989) and a memoir about love, loss, recovery – and dogs: 'Small Dogs Can Save Your Life' (2010).
Having made her name as a journalist, columnist and broadcaster, she turned her hand to writing fiction for adults and children. In 1985 she collaborated with Gerald Scarfe on a satire on Margaret Thatcher and her government, called 'Father Kissmas and Mother Claws.' Mooney's novels for adults are The Windsurf Boy (1983), The Anderson Question (1985), The Fourth of July (1988), Lost Footsteps (1993), Intimate Letters (1993) and The Invasion of Sand (2005). She is the author of the best-selling Kitty and Friends series of stories for young girls, including I Don't Want To! and So What?, which were inspired by her own daughter, Katherine. There were 13 volumes in all, published 1985–2002. She then went on to write a series of six books inspired by her small dog Bonnie, with titles like Big Dog Bonnie and Brave Dog Bonnie. In all, she published 26 books for children and young people. In addition, Bel Mooney has written many short stories for magazines and collections. Published in France as Petula, Big Dog Bonnie was shortlisted for the prestigious Prix Tam-Tam in France. Her fiction (adults and children) has been translated into twelve languages. Mooney has reviewed fiction and non-fiction for many newspapers including the Spectator, the Observer, the Times and the Times Literary Supplement. She has been a judge for the Whitbread (now Costa) Book of the Year (1986) and the Orange Prize (2008).
She was a regular broadcaster on BBC Radio 4 from 1982 until 2008, notably as presenter of Devout Sceptics, a programme devoted to public figures' private beliefs – the participants were not necessarily agnostic or atheistic, as the title might suggest. She also made many series for Channel 4 (for example Mothers By Daughters, 1983) and BBC2 (Grief, 1994) and one-off documentaries on people including Ellen Wilkinson MP and Dora Russell. In the '90s Mooney was interviewed many times on radio and television in connection with environmental campaigning. In particular she was involved, like her former husband, in the campaign against the Batheaston Bypass in the 1993–95. During the '80s and '90s she wrote six novels and made many programmes for television and for Radio 4.
In June 2007 she began writing a weekly column for the Saturday edition of the Daily Mail (after two years in the same role at the Times), advising readers on emotional and relationship issues, and she contributes other comment articles to the paper as well as regular book reviews.
Awards and charitable work
She was awarded the degree, Hon D.Litt, from the University of Bath in 1998 and appointed Honorary Fellow of Liverpool John Moores University in 2002 and is a Fellow of University College London. Devout Sceptics (BBC Radio 4) won a Sandford St Martin Trust award for religious broadcasting, and the children's novel The Voices of Silence won a New York Public Library Book of the Year citation and was shortlisted for a Gold Medal in the state of California. She has won special awards for journalism from charities including CRUSE. In the '90s she was involved in the establishment of a new literary festival in Bath, and introduced the first ever 'performer', Ted Hughes, in 1996. From 2002 until 2011 she was involved in charitable fund-raising in Bath, as Chairman of the Egg Appeal (to built a dedicated theatre for young people), as President of the Royal United Hospital appeal to build a new NICU (Neonatal Intensive Care) unit, and as Chair of the 2010 appeal to refurbish the Theatre Royal, Bath, Somerset. She served on the board of directors of that theatre until 2015. Mooney is also Patron of National Family Mediation (NFM) and Relate.
Mooney was married to the television journalist Jonathan Dimbleby for thirty-five years. During their married life they maintained an organic farm. The couple separated in 2004 after Jonathan Dimbleby's affair with opera singer Susan Chilcott; they divorced in 2006. Mooney and Dimbleby have two adult children, Kitty (born 1980), a freelance journalist and charity consultant and Daniel (born 1974), a television producer/director. On 8 September 2007, Mooney married Robin Allison-Smith, formerly a freelance photographer, now a businessman, with whom she lives on the outskirts of Bath, Somerset.