Hart left school in 1943 and wanted to join the Royal Air Force, but as he would have been unable to fly owing to slightly deficient eyesight, he followed in his father’s footsteps and joined the British Indian Army instead where he gained an officers’ commission in the 1st Gurkha Rifles. However, when he was told that lower-ranked British officers would be replaced by Indian officers following Indian independence, he decided to return to civilian life. The outbreak of the Korean War (25 June 1950) saw him being re-commissioned in the Territorial Army, attached to the Royal Artillery, from 23 November 1948 to 1 July 1950.

After being demobilised, Hart decided to become a professional artist and studied art at Maidstone College of Art, which later became Kent Institute of Art & Design (and is now the Maidstone campus of the University for the Creative Arts). He graduated in 1950 and, after working as a display artist in a London store, became a freelance artist.

Hart’s break into broadcast television work came in 1952, after his brother persuaded him to attend a party where he met a BBC children’s TV producer. After an interview, in which Hart drew a fish on a napkin while the producer was looking for paper, Hart became resident artist on the Saturday Special programme. Subsequent TV shows included Playbox (1954–59), Tich and Quackers, Vision On (1964–76) Take Hart (1977–83), Hartbeat (1984–93), Artbox Bunch (1995–96) and Smart Hart (1999–2000). From the 1970s, he often appeared alongside the animated Plasticine stop-motion character Morph, created by Peter Lord of Aardman Animations.

Hart met his wife, Jean Skingle, while working in television; they married in 1953. They were married for 50 years until she died in 2003. They had a daughter, Carolyn, and two grandchildren.

Hart was a regular face on the BBC children’s programme Blue Peter in the 1950s and presented a number of programmes in 1959. Richard Marson’s book Blue Peter: Inside the Archives lists Hart as a presenter in November 1959 but he is not officially listed as a host. As well as demonstrating small-scale projects (the type that viewers might be able to do), Hart also created large-scale artworks on the TV studio floor, and even used beaches and other open spaces as ‘canvases’.

Hart received two BAFTA awards. His first, for Best Children’s Educational Programme, came in 1984 for Take Hart, and he was given a Lifetime Achievement Award in 1998. He retired from regular TV work in 2001.

On 28 December 2006, it was announced during the reunion programme It Started with Swap Shop that Hart was in poor health, though this was not elaborated upon until an interview with The Times published on 30 September 2008, revealing that two strokes had robbed him of the use of his hands and left him unable to draw. He described this as “the greatest cross I have to bear”. Hart died peacefully on 18 January 2009 at the age of 83.

On 1 March 2009 a flash mob, organised through Facebook, paid tribute to Hart with around two hundred Morph figures displayed outside the Tate Modern art gallery. Hart’s daughter, Carolyn Ross, attended and judged the “Best Morph in Show”.

A memorial plaque is displayed in Hart’s birthplace, the town of Maidstone, where he studied art at the town’s art college. The plaque was unveiled by his daughter in May 2009 at the Hazlitt Arts Centre.

In September 2010 Tony Hart: A Portrait of My Dad, an affectionate biography of Hart by his daughter Carolyn, was published by John Blake Publishing.

In February 2015 a wave of tributes (followed by corrections) appeared on social media sites over a period of two days, when an individual mistakenly read a 2009 report of Hart’s death and, missing the dateline, published it as news on Facebook, from which it was later transferred to Twitter. Many social media posters hyperlinked to an article in The Guardian. The newspaper published a graph of the number of readers referred to its article for the period. Aardman Animations used its Twitter account, in the name of Morph, to point to a tribute to Tony Hart (a portrait of him being hung on a wall) that was included in the last episode of its forthcoming new set of episodes for the Morph television series.