Suchet has two brothers, one of whom is the actor David Suchet. He is father of broadcast journalist Rory Suchet and uncle of broadcast journalist Richard Suchet.
Suchet was born in London, the son of Joan Patricia (née Jarché; 1916–1992), an actress, and Jack Suchet, who emigrated from South Africa to England in 1932, and trained to be a doctor at St Mary's Hospital, London in 1933. Suchet's father was a consultant obstetrician and gynaecologist, working with Alexander Fleming on the role of penicillin in treating venereal disease. His maternal grandfather, James Jarché, was a famous Fleet Street photographer, notable for the first pictures of Edward VIII and Wallis Simpson and also for his pictures of Louis Blériot (1909) and the Siege of Sidney Street. Suchet's father was of Lithuanian Jewish descent, and his mother was English-born and Anglican (she was of Russian Jewish descent on her own father's side, and of English descent on her mother's side).
Suchet was brought up with his two brothers, Peter and David. He attended Uppingham School, Rutland before studying at Queen's College, Dundee (then a part of the University of St Andrews). He was awarded an honorary doctorate from the University of Dundee in 2000. Peter is an advertising executive, and his younger brother, David, is an actor, best known for his portrayal of Agatha Christie's Poirot.
Suchet began his career in journalism in 1967, when he was taken on as a graduate trainee by Reuters news agency. During that year he learned the rudiments of straightforward, unbiased news editing and reporting, under the tutelage of John Fawcus and Anton Wills-Eve.
He was on the Middle East desk at the time of the six days war in June that year, an event that taught him how to edit his copy that was fast, accurate and acceptable to newspapers in both Israel and the Arab world. This objective attitude towards journalism never left him.
Suchet is most famous for being a newsreader for ITV News from 1972 until 2004. During this time, he presented News at 12.30 / News at One and News at Ten, but became best known for presenting the Early Evening News between late 1991 (when it was introduced to replace the News At 5:40) and 1999 when the bulletin was dropped. Initially, he alternated with Carol Barnes as the regular presenter of the Early Evening News, but by 1994 he had become the sole main host and thereafter replaced predecessors Michael Nicholson and Alastair Stewart as "the face of the evening news".
He also anchored or contributed to countless special event programmes, including royal occasions (he was one of the main commentators on ITN's coverage of Princess Diana's funeral), the Budget and ITN's election coverage. He was voted fifth scariest TV and radio celebrity in the Radio Times poll.
He retired from ITN in March 2004 to work on his autobiography then made a return to TV news, presenting Five News, initially for a six-month period from January 2006, then extended to Christmas 2007.
Suchet has also been a guest presenter for ITV's This Morning, as well as being a guest panelist on Five's The Wright Stuff. He hosted the revival of the quiz show Going for Gold on Channel 5 and later Wordplay also on Channel 5.
On 20 February 2008, Suchet along with Alan Johnson were recognised by the Royal Television Society Television Journalism for the achievements throughout their careers. Suchet was recognised for his live coverage of the funeral of Diana, Princess of Wales and the undercover reporting in Afghanistan.
In July 2009, to coincide with the 40th anniversary of the NASA moon landings, ITN produced five special 10-minute programmes for ITV titled Mission to the Moon – News from 1969. Suchet, a former ITN newscaster, was the presenter of these specials. The first aired at 22:35 on ITV on Wednesday 15 July and ran across the following Thursday, Friday, Sunday and Monday evenings.
In July 2010, Suchet joined Classic FM as the regular host of the Sunday lunchtime music show (12:00-15:00). He first appeared on the station in 2004 as guest presenter of the Composer's Notes series in which he examined the finances and wealth of famous composers. In September 2010 it was announced that he would be presenting the Classic FM weekday morning show (9:00-13:00) from January 2011, taking over from the show's previous host Simon Bates. This quickly became Classic FM's most listened to show, with over 3 million listeners per week.
John Suchet is a fan of the composer Ludwig van Beethoven and has become one of the UK's leading experts on the composer and his works, publishing five books about the composer including the three-volume biographical novel "The Last Master". His book, The Last Waltz: The Strauss Dynasty and Vienna, is forthcoming (2016).
Suchet and his wife Bonnie have five grown-up sons between them from previous marriages. In 2006, Bonnie was diagnosed with Alzheimer's disease in her early 60s. Suchet appeared on the mainstream ITN / ITV and BBC news bulletins on 17 February 2009 to talk about this, to raise awareness of the disease and to campaign on behalf of Admiral Nurses. He explained that Bonnie would have no idea that he was on the news programmes. Bonnie died on 15 April 2015, aged 73.
Suchet is a huge fan of – and writer on – Ludwig van Beethoven and has toured with his material. He lives in Docklands, London.