Winner was an only child, born in Hampstead, London, England, to Helen (née Zlota) and George Joseph Winner (1910–1975), a company Director. His family was Jewish; his mother was Polish and his father of Russian extraction. Following his father's death, Winner's mother gambled recklessly and sold art and furniture worth around £10m at the time, bequeathed to her not only for her life but to Michael thereafter. She died aged 78 in 1984.

He was educated at St Christopher School, Letchworth, and Downing College, Cambridge, where he read law and economics. He also edited the university's student newspaper, Varsity (he was the youngest ever Editor up to that time, both in age and in terms of his university career, being only in the second term of his second year). Winner had earlier written a newspaper column, 'Michael Winner's Showbiz Gossip,' in the Kensington Post from the age of 14. The first issue of Showgirl Glamour Revue in 1955 has him writing another film and showbusiness gossip column, "Winner's World". Such jobs allowed him to meet and interview several leading film personalities, including James Stewart and Marlene Dietrich. He also wrote for the New Musical Express.

He began his screen career as an assistant Director of BBC television programmes, cinema shorts, and full-length "B" productions, occasionally writing screenplays. He directed his first travelogue, This is Belgium (1957), which was largely shot on location in East Grinstead. His first on-screen credit was earned as a Writer for the crime film Man with a Gun (1958) directed by Montgomery Tully. Winner's first credit on a cinema short was Associate Producer on Floating Fortress (1959) produced by Harold Baim. Winner's first project as a lead Director, Shoot to Kill (1960), was based on another of his stories.

In the early 1960s, Winner's films followed fashion. His second project, Some Like It Cool (1961), is the tale of a young woman who introduces her prudish husband and in-laws to the joys of nudism. Filmed at Longleat, he was afraid the sight of bare flesh would offend the magistrate for the area so he confided his worries to the landowner. "Don’t worry," said the Marquess, "I am the local magistrate".

After releasing family drama Old Mac and a mystery called Out of the Shadow (both 1961), Winner brushed with Gilbert and Sullivan, writing the screenplay and directing a version of The Mikado titled The Cool Mikado (1963), starring Frankie Howerd which was produced by Harold Baim. It was preceded by the Billy Fury-led musical Play It Cool (1962) and comedy short Behave Yourself (1962). His first significant project was West 11 (1963), a realistic tale of London drifters starring Alfred Lynch.

Winner's film The System (1964) began a partnership with actor Oliver Reed that would last for six films over a 25-year period. Winner and Reed closed out the 1960s as a pair with The Jokers (1967, also starring Michael Crawford), comedy-drama I'll Never Forget What's'isname (1967), and the World War II satire Hannibal Brooks (1969). A non-Reed comedy, You Must Be Joking! (1965) with Denholm Elliott, and an ambitious Olympic drama, The Games (1970), were also made.

The turning point came when he first directed Marlon Brando in The Nightcomers (1971), a prequel to The Turn of the Screw by Henry James, the first of many films for which he was credited as Editor using the pseudonym "Arnold Crust". He then made his earliest efforts with Charles Bronson in Chato's Land (1972), recounting a mixed race American Indian fighting with Whites, and The Mechanic (also 1972), a thriller in which professional assassins are depicted. The following year, Winner cast Lancaster again in the espionage drama Scorpio, and worked with Bronson on The Stone Killer, in collaboration with Producer Dino De Laurentiis.

Winner and Bronson collaborated on Death Wish (1974), a film that defined the subsequent careers of both men. Based on a novel by Brian Garfield and adapted to the screen by Wendell Mayes, Death Wish was originally planned for Director Sidney Lumet, under contract with United Artists. The commitment of Lumet to another film and UA's questioning of its subject matter led to the film's eventual production by Dino De Laurentiis through Paramount Pictures. Death Wish follows Paul Kersey, a liberal New York Architect who becomes a gun-wielding vigilante after his wife is murdered and daughter is raped. With a script adjusted to Bronson's persona, the film generated controversy during its screenings and was one of the year's highest grossers.

Following the release of Death Wish, Winner became primarily known as an action film Director. Most of his attempts to branch into other genres were unsuccessful. Won Ton Ton, the Dog Who Saved Hollywood (1976), an animal comedy starring Bruce Dern, Madeline Kahn, Art Carney, and Milton Berle, intended as a satire of Hollywood, was a financial failure. Of modest success was his horror film The Sentinel (1977), the remake of Raymond Chandler's novel The Big Sleep (1978), and the organized crime thriller Firepower (1979) with Sophia Loren.

As with fellow British Director J. Lee Thompson, Cannon Films became Winner's mainstay during the 1980s. Two failures followed, a 1983 remake of 1945's The Wicked Lady with Faye Dunaway and the generic thriller Scream for Help (1984). Winner made a final splash, however, with Death Wish 3 (1985), which although set in New York City, was mostly filmed in London for budgetary reasons.

Winner's output declined after Death Wish 3. He directed adaptations of the Alan Ayckbourn musical play A Chorus of Disapproval (1989) with Anthony Hopkins and the Agatha Christie novel Appointment with Death (1988). Winner was also attached to direct Cannon's 1990 film Captain America, from a James Silke script, which he would revise with Stan Hey, and then Stan Lee and Lawrence Block. By 1987, however, Winner was off the project and did Appointment with Death instead.

After Cannon Films entered bankruptcy, Winner confined himself to British productions with the Michael Caine and Roger Moore farce Bullseye! (1990), Dirty Weekend (1993) starring Lia Williams, and Parting Shots (1999). In 1994 he appeared as a guest Artist alongside Joan Collins, Christopher Biggins and Marc Sinden (who in 1983 had appeared in Winner's The Wicked Lady) in Steven Berkoff's film version of his own play Decadence.

Winner was an active proponent of law enforcement issues and established the Police Memorial Trust after WPC Yvonne Fletcher was murdered in 1984. Thirty-six local memorials honouring police officers who died in the line of duty have been erected since 1985, beginning with Fletcher's in St. James's Square, London. The National Police Memorial, opposite St. James's Park at the junction of Horse Guards Road and The Mall, was also unveiled by Queen Elizabeth II on 26 April 2005.

In 2006, it was revealed that Winner had been offered but declined an OBE in the Queen's Birthday Honours for his part in campaigning for the Police Memorial Trust. Winner remarked "An OBE is what you get if you clean the toilets well at King's Cross station." Winner subsequently alleged (on his Twitter page) that he had also turned down a knighthood.

On 1 January 2007, Winner acquired the bacterial infection Vibrio vulnificus from eating an oyster in Barbados. He almost had a leg amputated and verged on the brink of death several times. Before recovering, Winner was infected with the "hospital superbug" MRSA. In September 2011, Winner was also admitted to hospital with food poisoning after eating steak tartare, a raw meat dish, four days in a row. The dish is not recommended for those with a weak immune system and in retrospect Winner regarded his decision to eat it as "stupid".

Winner lived in the former home of Painter Luke Fildes in Holland Park, Woodland House, designed for Fildes by Richard Norman Shaw. It was announced in 2008 that Winner intended to leave his house as a museum, but discussions with Kensington and Chelsea council apparently stalled after they were unable to meet the £15 million cost of purchasing the freehold of the property, which expires in 2046.

Winner was an outspoken character. He was a member of the Conservative Party and supporter of Prime Minister Margaret Thatcher. Winner was praised for having liberal views on gay rights, in particular during an episode of Richard Littlejohn Live and Uncut, where he attacked the presenter (who had been in the midst of an attack on two lesbian guests) for his stance on same-gender marriage and parenting, going so far as to say to him "[they] have come across with considerable dignity and you have come across as an arsehole." After Winner's death, this moment was brought up many times in eulogies to him. In a 2009 interview with the Telegraph he bemoaned political correctness and said if he was Prime Minister he would be "to the right of Hitler".

Winner remained prominent in British life for other reasons, including his outspoken restaurant reviews. His fame as a restaurant critic was such that, at a Cornwall cafe, an unconsumed piece of his serving of lemon drizzle cake was incorporated into the Museum of Celebrity Leftovers. Winner wrote his column, "Winner's Dinners", in The Sunday Times for more than twenty years. On 2 December 2012 he announced that he was to contribute his last review because of poor health, which had put him in hospital eight times in the previous seven months.

In an interview with The Times newspaper in October 2012, Winner said liver specialists had told him that he had between 18 months and two years to live. He said he had researched assisted suicide offered at the Dignitas clinic in Switzerland, but found the bureaucracy of the process off-putting. Winner died at his home, Woodland House in Holland Park, on 21 January 2013, aged 77. Winner was buried following a traditional Jewish funeral at Willesden Jewish Cemetery.

Following the allegations made against Harvey Weinstein in October 2017, Winner was accused by three women, Debbie Arnold, Cindy Marshall-Day and an unidentified woman, of demanding they expose their breasts to him, in Arnold's case during an audition at his home. The two named women refused.

He was a regular panellist on BBC Radio 4’s Any Questions and later appeared on television programmes including the BBC TV’s Question Time and Have I Got News for You. He was an honorary member of BAFTA and of the Directors Guild of Great Britain. His autobiography Winner Takes All: A Life of Sorts was published by Robson Books in 2006. The book largely describes his experiences with many big-screen actors. He also wrote a dieting book, The Fat Pig Diet Book. He also featured in TV commercials that he himself directed for insurance company esure between 2002 and 2009, with his trade-mark catchphrase "Calm down, dear! It's just a commercial!". He is referred to repeatedly in the QI episode "Illness".