Goldacre was educated at Magdalen College School, Oxford then studied medicine at Magdalen College, Oxford where he obtained a first class degree in his preclinical studies in 1995. While at Oxford he also edited the student magazine Isis. Before going on to clinical medicine at University College London, he was a visiting researcher in cognitive neuroscience at the University of Milan, working on fMRI brain scans of language and executive function. He received a master's degree in philosophy (funded by the British Academy) from King's College London. He passed the MRCPsych Part II examinations in December 2005 and became a member of the Royal College of Psychiatrists. In 2008 he was a research fellow at the Institute of Psychiatry, King's College London. , Goldacre is a psychiatric registrar and Guardian research fellow at Nuffield College, Oxford.

Goldacre writes a weekly column, Bad Science, in the Saturday edition of The Guardian newspaper, and publishes expanded versions of the columns with reader comments on his website badscience.net. Devoted to satirical criticism of scientific inaccuracy, health scares, pseudoscience and quackery, it focuses especially on examples from the mass media, consumer product marketing, problems with the pharmaceutical industry and its relationship to medical journals, and complementary and alternative medicine in Britain. On the controversial topic of water fluoridation, he stated in 2008 that "anyone making any confident statement on fluoride speaks way beyond the evidence".

He has been a particular critic of the claims of television nutritionist Gillian McKeith, anti-immunisation campaigners (particularly followers of Andrew Wakefield such as Melanie Phillips and Jeni Barnett), Brain Gym, bogus positive MRSA swab stories in tabloids, antidepressants, publication bias, and the makers of the product Penta Water. While investigating McKeith's membership of the American Association of Nutritional Consultants, Goldacre purchased a "certified professional membership" on behalf of his late cat, Henrietta, from the same institution for $60. In February 2007, McKeith agreed to stop using the title "Dr" in her advertising following a complaint to the Advertising Standards Authority by a Bad Science reader.

In 2008, vitamin entrepreneur Matthias Rath sued Goldacre and The Guardian over three articles in which Goldacre criticised Rath's promotion of vitamin pills to AIDS sufferers in South African townships. Rath dropped his action in September 2008 and was ordered to pay initial costs of £220,000 to the Guardian. The paper is seeking full costs of £500,000, and Goldacre has expressed an interest in writing a book about Rath and South Africa, as a chapter on the subject had to be cut from his book while the litigation proceeded. The chapter was reinstated in a later edition of the book, and also published online.

In his spare time, Goldacre frequently delivers free talks about bad science — he describes himself as a "nerd evangelist".

Goldacre's book Bad Science was published by Fourth Estate in September 2008. The book contains extended and revised versions of many of his Guardian columns. It has been positively reviewed by the BMJ and Daily Telegraph and has reached the Top 10 bestseller list for Amazon Books. In an interview in 2008, Goldacre stated that "one of the central themes of my book [Bad Science] is that there are no real differences between the $600 billion pharmaceutical industry and the $50 billion food supplement pill industry".

Goldacre has also contributed to The Atheist's Guide to Christmas, a charity book featuring essays and anecdotes from 42 well-known atheists, on the subject of "the power of ideas." He also wrote the foreword to the reprint edition of Testing Treatments: Better Research for Better Healthcare by Imogen Evans, Hazel Thornton and Iain Chalmers, published by Pinter & Martin in March 2010.

Goldacre has won several awards for his journalism, including:

• Association of British Science Writers award for Best Feature 2003 for his article "Never mind the facts"
• Association of British Science Writers award for Best Feature 2005 for his article "Don't dumb me down"
• Freelance of 2006 at the Medical Journalism Awards
• The inaugural Statistical Excellence In Journalism Award of the Royal Statistical Society for his article "When the facts get in the way of a story"
• the HealthWatch Award for "significant steps in improving the public's understanding of health issues"
• Honorary Doctor of Science at Heriot Watt University (June 2009) "in recognition of his outstanding contribution to scientific journalism and in the promotion of public engagement with and greater understanding of science."
• Honorary Doctor of Science at Loughborough University (July 2010) "in recognition of his outstanding contribution to science and journalism"