Gambaccini's broadcasting career began at Dartmouth College, where he was music director of the now-defunct WDCR, a college-owned-and-operated Top 40 radio station.

[4] Having left Oxford, Gambaccini considered further study in law at Harvard or Yale, but had the opportunity of writing for Rolling Stone magazine, as British correspondent.

[5][6] Gambaccini then started broadcasting in the UK, on BBC Radio 1, from September 1974, first as a music reporter on the John Peel Saturday show Rockspeak[citation needed] and as presenter of All American Heroes.

[citation needed] He has worked widely across the BBC and the British Forces Broadcasting Service (BFBS) as well as contributing to many television shows, mostly related to music, film, and the arts.

In March 2008, he took over as chairman of the Radio 4 music quiz Counterpoint from Edward Seckerson; he was temporarily replaced in 2013 by Russell Davies and returned to the show in November 2014 after being cleared of allegations of historical sexual offences made against him.

He returned to BBC Radio 2 with America's Greatest Hits on 15 November 2014, and hosted it until 2 July 2016, when he took over Pick of the Pops from Tony Blackburn, the following week.

He started his final America's Greatest Hits on the BBC with "Born to Run" by Bruce Springsteen & the E Street Band, and ended it with Justin Timberlake's "Can't Stop The Feeling!".

On Boxing Day 2021, he co-presented a special show on Greatest Hits Radio paying tribute to Janice Long, whom he had discovered in 1982.

Gambaccini was co-author of The Guinness Book of British Hit Singles and related titles, with Tim and Jo Rice, alongside Radio 1 colleague at that time, Mike Read, between 1977 and 1996.

The Ultimate Man, a musical about a comic book superhero, was co-written with Alastair King and Jane Edith Wilson, and produced at the Bridewell Theatre in London in 2000.

"[21] In fact, the symbol was a general indication that the subject should not be promoted or transferred without reference to the department responsible for security vetting, due to left-leaning sympathies (see: "Christmas tree" files).

[20] On 1 November 2013, it was reported that Gambaccini had been arrested on suspicion of historical sexual offences as part of an investigation by Operation Yewtree in the United Kingdom.

[23] Giving evidence to the House of Commons Home Affairs Select Committee on 3 March 2015, Gambaccini said he believed he was used as "human fly paper" to encourage other people to come forward and make allegations against him.

[24] The BBC reported that he also said he suspected his bail was repeatedly extended until the end of high-profile cases involving other celebrities because "police did not want juries to hear a former Radio 1 DJ had been cleared of sexual wrongdoing".

[27][28] In February 2016, Irish Supreme Court Judge Adrian Hardiman used a review of the book to criticize what he described as the radical undermining of the presumption of innocence, especially in sex cases, including Gambaccini's, by the methods used in Operation Yewtree (among other instances).

[30] In November 2018, he settled a claim against the Crown Prosecution Service, who agreed to pay him damages; the amount was not disclosed due to confidentiality clauses in the settlement agreement.