Beginning with the best-seller Fatherland, Harris focused on events surrounding the Second World War, followed by works set in ancient Rome.

Several of Harris's novels have been adapted into visual media, with the most prominent being The Ghost Writer (2010) and An Officer and a Spy (2019), which he co-wrote the screenplays with director Roman Polanski, and Conclave (2024).

After leaving Cambridge, Harris joined the BBC and worked on news and current affairs programmes such as Panorama and Newsnight.

Harris co-wrote his first book, A Higher Form of Killing (1982), with fellow BBC journalist Jeremy Paxman: this was a study of chemical and biological warfare.

The Government, the Media and the Falklands Crisis (1983) covering the Falklands War; The Making of Neil Kinnock (1984), a profile of Kinnock just after he became leader of the Opposition; Selling Hitler (1986), an investigation of the Hitler Diaries scandal; and Good and Faithful Servant (1990), a study of Bernard Ingham, press secretary to Margaret Thatcher while she was prime minister.

[4] Harris has stated that the proceeds from the book enabled him to buy a former vicarage in Berkshire that he jokingly dubbed "the house that Hitler built", where he still lives.

In 2006, Harris followed up on Pompeii with another Roman-era work, Imperium, the first novel in a trilogy centred on the life of the great Roman orator and lawyer Marcus Tullius Cicero.

Harris was an early and enthusiastic supporter of Tony Blair (a personal acquaintance) and a donor to New Labour, but the war in Iraq blunted his enthusiasm.

The title refers both to a professional ghostwriter, whose lengthy memorandum forms the novel, and to his immediate predecessor who, as the action opens, has just drowned in gruesome and mysterious circumstances.

The dead man has been ghosting the autobiography of a recently unseated British prime minister called Adam Lang, a thinly veiled version of Blair.

"[11] Harris said in a U.S. National Public Radio interview that politicians like Lang and Blair, particularly when they have been in office for a long time, become divorced from everyday reality, read little and end up with a pretty limited overall outlook.

[13] The New York Observer, headlining its otherwise hostile review The Blair Snitch Project, commented that the book's "shock-horror revelation" was "so shocking it simply can't be true, though if it were it would certainly explain pretty much everything about the recent history of Great Britain.

He gradually realises that Alfred Dreyfus has been unjustly imprisoned for acts of espionage committed by another man who is still free and still spying for the Germans.

[21] The film adaptation, starring Ralph Fiennes and Stanley Tucci and directed by Edward Berger, released in the US by Focus Features[22] on 1 November 2024.

The story is told through the eyes of two young civil servants – one German, Hartmann, and one English, Legat, who reunite at the fateful summit, six years after they were friends at university.

V2, published on 17 September 2020,[27] is a thriller set in November 1944 which follows the parallel stories of a German V-2 rocket scientist, Rudi Graf, and a British WAAF, Kay Caton-Walsh.

Act of Oblivion, published on 1 September 2022,[28] is set in 1660 and follows Richard Nayler of the Privy Council who is tasked with tracking down the regicides Edward Whalley and William Goffe.

It follows a young British intelligence officer on the eve of World War I who is assigned to investigate the disappearance of top-secret documents during Prime Minister H. H. Asquith's affair with Venetia Stanley.

They co-wrote a script and Polanski announced filming for early 2008, with Nicolas Cage, Pierce Brosnan, Tilda Swinton and Kim Cattrall starring.

The film, titled The Ghost Writer in all territories except the UK, was shot in early 2009 in Berlin and on the island of Sylt in the North Sea, which stood in for London and Martha's Vineyard respectively, owing to Polanski's inability to travel legally to those places.

On 2 December 2010, Harris appeared on the radio programme Desert Island Discs, when he spoke about his childhood and his friendships with Tony Blair and Roman Polanski.