Television
Shaw began television work in 1967. Parts in one-off plays for Granada Television led to his playing hippy student Robert Croft, Lucile Hewitt's boyfriend, in Coronation Street. Another early role was booze and football-loving Welsh medical student Huw Evans in the television comedy series Doctor in the House. He later guest-starred, playing the same role, in the follow-up series Doctor at Large, now a nervous expectant father in the episode "Mother and Father Doing Well". The actor had been introduced to international audiences via his portrayal of Horatio in the 1970 Hallmark Hall of Fame presentation of Hamlet, starring Richard Chamberlain.
Shaw appeared with future co-star Lewis Collins in an episode of The New Avengers. Both played the roles of terrorists. Shaw portrayed Ray Doyle ("Agent 4-5") in the British television series The Professionals (1977–1983), opposite Collins. Shaw played another law-enforcement role in the 1990s ITV production The Chief.
In 1983, Shaw played Robert Falcon Scott in The Last Place on Earth. The series was filmed at Frobisher Bay near the city of Iqaluit on Baffin Island, Canada. In interview at the time, Shaw commented that he generally responded well to the testing physical conditions, particularly when they enhanced the reality of the scene. In the same year he played Sir Henry Baskerville in The Hound of the Baskervilles, an adaptation of the novel by Sir Arthur Conan Doyle. He acted opposite Ian Richardson's Sherlock Holmes and Donald Churchill's Dr. Watson.
He played Cecil Rhodes in Rhodes, an eight-part serial that aired in 1996 and was filmed on location in South Africa. Shaw's younger son, Joe, took early leave of his drama school course to play the part of the youthful Rhodes.
Another television acting credit includes the role of Mr (later Prof) Robert Kingsford in Always and Everyone (1999–2002), a British accident and emergency medical series, played alongside Niamh Cusack.
In 2001, he took the title role in the BBC drama Judge John Deed. The character gave an editorial voice to the television writer and producer G.F. Newman's ideas about lifestyle choices such as vegetarianism and alternative medicine as well as issues of social justice. One episode about the safety of the MMR vaccine was banned.
Between seasons of Judge John Deed, Shaw took the role of poetic bespectacled forensic detective Adam Dalgliesh in P.D. James's Death in Holy Orders in 2003 and The Murder Room in 2005. After the sixth season of Judge John Deed had been filmed, Shaw appeared in the series Apparitions, broadcast by the BBC in 2008. This was Shaw's first project as executive director.
From 2007 until 2017 he played the title role in the BBC TV series Inspector George Gently.
On 9 May 2015 Shaw recited "For the Fallen" at VE Day 70: A Party to Remember in Horse Guards Parade, London which was broadcast on BBC 1.
In 2021 he played the role of Dennis Stephenson, leader of a fictitious religious cult called the Barum Brethren, in the BritBox original series The Long Call. The series premiered in autumn 2021, and is based on the Ann Cleeves bestselling novel.
