Bentine was born in Watford, Hertfordshire, to a Peruvian father, Adam Bentin, and a British mother, Florence Dawkins, and grew up in Folkestone, Kent. He was educated at Eton College. With the help of speech trainer, Harry Burgess, he overcame a stammer and subsequently developed an interest in amateur theatricals, along with the Tomlinson family, including the young David Tomlinson. He spoke fluent Spanish and French. His father was an early aeronautical engineer for the Sopwith Aviation Company during and after World War I and invented a tensometer for setting the tension on aircraft rigging wires.
In World War II, he volunteered for all services when the war broke out (the RAF was his first choice owing to the influence of his father's experience), but was initially rejected because of his father's nationality.
He started his acting career in 1940, in a touring company in Cardiff playing a juvenile lead in Sweet Lavender. He went on to join Robert Atkin's Shakespearean company in Regent's Park, London, until he was called up for service in the RAF. He was appearing in a Shakespearean play in doublet and hose in the open-air theatre in London's Hyde Park when two RAF MPs marched on stage and arrested him for desertion. Unknown to him, an RAF conscription notice had been following him for a month as his company toured.
Once in the RAF he went through flying training. He was the penultimate man going through a medical line receiving inoculations for typhoid with the other flight candidates in his class (they were going to Canada to receive new aircraft) when the vaccine ran out. They refilled the bottle to inoculate him and the other man as well. By mistake they loaded a pure culture of typhoid. The other man died immediately, and Bentine was in a coma for six weeks. When he regained consciousness his eyesight was ruined, leaving him myopic for the rest of his life. Since he was no longer physically qualified for flying, he was transferred to RAF Intelligence and seconded to MI9, a unit that was dedicated to supporting resistance movements and helping prisoners escape. His immediate superior was the Colditz escapee Airey Neave.
At the end of the war, he took part in the liberation of Bergen-Belsen concentration camp. He said about this experience:
Millions of words have been written about these horror camps, many of them by inmates of those unbelievable places. I’ve tried, without success, to describe it from my own point of view, but the words won’t come. To me Belsen was the ultimate blasphemy. (The Reluctant Jester
, Chapter 17.)
After the war he decided to become a comedian and worked in the Windmill Theatre where he met Harry Secombe. He specialised in off-the-wall humour, often involving cartoons and other types of animation. His acts included giving lectures in an invented language called Slobodian, "Imaginative Young Man with a Walking Stick" and "The Chairback", with a broken chairback having a number of uses from comb to machine gun and taking on a demonical life of its own. Peter Sellers told him this was the inspiration for the prosthetic arm routine in Dr Strangelove. This act led to his engagement by Val Parnell to appear in the Starlight Roof revues starring Vic Oliver, where he met and married his second wife Clementina, with whom he had four children. Also on the bill were Fred Emney and a young Julie Andrews.
He co-founded The Goon Show radio show with Spike Milligan, Peter Sellers and Harry Secombe, but appeared in only the first 38 shows on the BBC Light Programme from 1951 to 1953. The first of these shows were actually called Crazy People and subtitled "The Junior Crazy Gang"; the term "Goon" was used as the headline of a review of Bentine's act by Picture Post dated 5 November 1948. Only one of this first series (and very few of the following three in which he did not appear) has survived, the rest of the original disc recordings having apparently been destroyed or discarded as no longer usable, so there is almost no record of his work as a radio "Goon". He also appeared in the Goon Show film Down Among the Z Men.
In 1951 Bentine was invited to the United States to appear on The Ed Sullivan Show. On his return he parted amicably from his partners and continued touring in variety, remaining close to Secombe and Sellers for the rest of his life. In 1972, Secombe and Sellers told Michael Parkinson that Bentine was "always calling everyone a genius" and, since he was the only one of the four with a "proper education", they always believed him.
His first appearances on television were as presenter on a 13-part children's series featuring remote controlled puppets, The Bumblies, which he also devised, designed and wrote. These were three small creatures from outer space who slept on "Professor Bentine's" ceiling and who had come to Earth to learn the ways of Earthling children. Angelo de Calferta modelled the puppets from Bentine's designs and Richard Dendy moulded them in latex rubber. He sold the series to the BBC for less than they had cost to make. He then spent two years touring in Australia (1954–55).
On his return to Britain in 1954, he found he faced hostility for having left the Goons to the extent that his picture had been excised from early pictures and wasn't replaced until Bentine complained to BBC Director-General Michael Checkland in the 1990s. He worked as a scriptwriter for Peter Sellers and then on 39 episodes of his own radio show Round the Bend in 30 Minutes, which has also been wiped from the BBC archive. He then teamed up with Dick Lester to devise a series of six TV programmes Before Midnight for Associated British Corporation (ABC) in Birmingham in 1958. This led to a 13-programme series called After Hours in which he appeared alongside Dick Emery, Clive Dunn, David Lodge, Joe Gibbons and Benny Lee. The show featured the "olde English sport of drats, later known as nurdling". Some of the sketches were adapted into a stage revue, Don't Shoot, We're British. He also appeared in the film comedy Raising a Riot, starring Kenneth More, which featured his five-year-old daughter "Fusty". He joked that she got better billing.
From 1960 to 1964, he had a television series, It's a Square World, which won a BAFTA award in 1962 and Grand Prix de la Presse at Montreux in 1963. A prominent feature of the series was the imaginary flea circus where plays were enacted on tiny sets using nothing but special effects to show the movement of things too small to see and sounds with Bentine's commentary. The plays were not serious. One, titled The Beast of the Black Bog Tarn, was set in a (miniature) haunted house.
He was the subject of This Is Your Life in April 1963 when he was surprised by Eamonn Andrews at the BBC Television Theatre.
In 1969-70 he was presenter of The Golden Silents on BBC TV, which attempted authentic showings of silent films, without the commentaries with which they were usually shown on television before then.
From 1974 to 1980 he wrote, designed, narrated and presented the children's television programme Michael Bentine's Potty Time and made one-off comedy specials.
From January to May 1984 Bentine put out 11 half-hour episodes, in two series, of The Michael Bentine Show on Radio 4. These have subsequently been repeated, several times, on the BBC's archive radio station BBC7 (now BBC Radio 4 Extra).
He was also the best-selling writer of 16 novels, comedies and non-fiction books. Four of his books, The Long Banana Skin (1975), The Door Marked Summer (1981), Doors to the Mind and The Reluctant Jester (1992) are autobiographical.
In 1968, travelling on the British Hovercraft Corporation (BHC) SR.N6, GH2012, he took part in the first hovercraft expedition up the River Amazon.
In 1995, Bentine received a CBE from Queen Elizabeth II "for services to entertainment". He was also a holder of the Peruvian Order of Merit, as was his grandfather, Don Antonio Bentin Palamero, for his work leading the fundraising for the Peruvian Earthquake Appeal.
Bentine was a crack pistol shot and helped to start the idea of a counter-terrorist wing within 22 SAS Regiment. In doing so, he became the first non-SAS person ever to fire a gun inside the close-quarters battle training house at Hereford.
His interests included parapsychology. This was as a result of his and his family's extensive research into the paranormal, which resulted in his writing The Door Marked Summer and The Doors of the Mind. He was, for the final years of his life, president of the Association for the Scientific Study of Anomalous Phenomena.
Bentine was also interested in science. On 14 December 1977, he appeared with Arthur C. Clarke on Patrick Moore's BBC The Sky At Night programme. The broadcast was entitled "Suns, Spaceships and Bug-Eyed Monsters" - a light-hearted look at how science fiction had become science fact, as well as how ideas of space travel had become reality through the 20th century. In the opening of the programme, Patrick Moore introduces Bentine with Bentine confirming that he was the possessor of a "Readers Digest Degree." This remark was typical of Bentine's comic overtones to most things in life whilst ensuring that he hid his undoubted talent and knowledge of science. Bentine appeared in a subsequent broadcast on a similar theme with Patrick Moore in 1980. Following the death of Arthur C. Clarke, BBC Sky At Night magazine released a copy of the 1977 archive programme on the cover of their May 2008 edition.
Bentine was married twice, remaining with his second wife, Clementina Stuart, a Royal Ballet dancer, for over fifty years. He had a child from his first marriage, Elaine, from whom he had a granddaughter, Marie Laurence, and three great-grandsons, William, Arthur and Nicholas. His children from his second marriage were better known by their family nicknames than their birth names: Gus (real name Stewart), Fusty (real name Marylla), Suki (real name Serena) and Peski (real name Richard). Two of his five children, his eldest daughters, died from cancer (breast cancer and lymphoma), while his elder son, Gus, was killed when a Piper PA-18 Super Cub, registration G-AYPN, crashed into a hillside at Ditcham Park Woods near Petersfield, Hampshire, on 28 August 1971. His body, together with that of his pilot friend Andy, and the aircraft, was found on 31 October 1971. The AAIB after an 11-month investigation found that the aircraft went into cloud when taking action to avoid power cables while flying low in poor visibility and subsequently went out of control.
Bentine's subsequent investigation into regulations governing private airfields resulted in his writing a report for Special Branch into the use of personal aircraft in smuggling operations. He fictionalised much of the material in his novel Lords of the Levels.
When his son Richard's first boy Elliot was born, he tried to give him an MG 08 machine gun, which his daughter-in-law refused to accept. When Richard's second son Harry was born, Michael bought him a train set.
From 1975 until his death in 1996, he and his wife spent their winters at a second home in Palm Springs, California, USA.
Shortly before his death from prostate cancer at the age of 74, he was visited in hospital by Prince Charles, who was a close friend, as well as a devoted fan of the Goons.
Some of the programmes Bentine appeared in were:The Great Bong (1993)
Terry Teo (1985)
The Sky At Night (1980)
The Sky At Night (1977)
Michael Bentine's Potty Time (1973–80)
The Golden Silents (1969–70)
All Square (1966)
It's a Square World (1960–64)
Round the Bend in Thirty Minutes (1959)
After Hours (1958–59)
Yes, It's the Cathode-Ray Tube Show! (1957)
The Bumblies (1954)
The Goon Show (1951–52)
Bachelor of Arts (short) (1971)
The Sandwich Man (1966)
We Joined the Navy (1962) (uncredited)
The Do-It-Yourself Cartoon Kit (1961)
I Only Arsked! (1958)
Raising a Riot (1955)
John and Julie (1955)
Forces' Sweetheart (1953)
Down Among the Z Men aka The Goon Movie (1952)
Cookery Nook (1951)
The Reluctant Jester sub-title My Head-on Collision with the 20th Century - Bantam Press - 1992 - ISBN 0-593-02042-1
Open Your Mind sub-title The quest for creative thinking - Bantam Press - 1990 - ISBN 0-593-01538-X
Templar - Bantam Press - 1988 - ISBN 0-593-01339-5
The Condor and The Cross sub-title An Adventure Novel of the Conquistadors - Bantam Press - 1987 - ISBN 0-593-01265-8
Lords of The Levels - Grafton - 1986 - ISBN 0-586-06643-8
The Shy Person's Guide To Life - Grafton - 1984 - ISBN 0-586-06167-3
Doors of The Mind - Granada - 1984 - ISBN 0-246-11845-8
The Door Marked Summer - Granada - 1981 - ISBN 0-246-11405-3
Smith & Son Removers - Corgi - 1981 - ISBN 0-552-12074-X
The Long Banana Skin - New English Library - 1976 - ISBN 0-450-02882-8
Madame's Girls and other stories (1980)
The Best of Bentine (1984) Panther
The Potty Encyclopedia (1985)
The Potty Khyber Pass (1974)
The Potty Treasure Island (1973)
Square Games (1966) Wolfe SBN 072340080-6
Michael Bentine's Book of Square Holidays M. Bentine & J. Ennis (1968) Wolfe SBN 72340019-9
Fifty Years on the Streets Michael Bentine & John Ennis (1964) New English Library, A Four Square Book