Banksy started as a freehand graffiti artist in 1990–1994 as one of Bristol’s DryBreadZ Crew (DBZ), with two other artists known as Kato and Tes. He was inspired by local artists and his work was part of the larger Bristol underground scene with Nick Walker, Inkie and 3D. During this time he met Bristol photographer Steve Lazarides, who began selling Banksy’s work, later becoming his agent. By 2000 he had turned to the art of stencilling after realising how much less time it took to complete a work. He claims he changed to stencilling while hiding from the police under a rubbish lorry, when he noticed the stencilled serial number and by employing this technique, he soon became more widely noticed for his art around Bristol and London. He was the goalkeeper for the Easton Cowboys and Cowgirls football team in the 1990s, and toured with the club to Mexico in 2001. Banksy’s first known large wall mural was The Mild Mild West painted in 1997 to cover advertising of a former solicitors’ office on Stokes Croft in Bristol. It depicts a teddy bear lobbing a Molotov cocktail at three riot police.

On 19 July 2002, Banksy’s first Los Angeles exhibition debuted at 33⁄3 Gallery, a tiny Silver Lake venue owned by Frank Sosa and was on view until 18 August. The exhibition, entitled Existencilism, “an Exhibition of Art, Lies and Deviousness” was curated by 33⁄3 Gallery, Malathion LA’s Chris Vargas, Funk Lazy Promotions’ Grace Jehan, and B+. The flyer of the exhibition indicates an opening reception was followed by a performance by Money Mark with DJ’s Jun, AL Jackson, Rhettmatic, J.Rocc, Coleman. Some of the paintings exhibited included Smiley Copper H (2002), Leopard and Barcode (2002), Bomb Hugger (2002), and Love is in the Air (2002).

Banksy’s name and identity remain unconfirmed and the subject of speculation. In a 2003 interview with Simon Hattenstone of The Guardian, Banksy is described as “white, 28, scruffy casual—jeans, T-shirt, a silver tooth, silver chain and silver earring. He looks like a cross between Jimmy Nail and Mike Skinner of the Streets.” Banksy began as an artist at the age of 14, was expelled from school, and served time in prison for petty crime. According to Hattenstone, “anonymity is vital to him because graffiti is illegal”. For 10 years in the late 1990s, Banksy lived in Easton, Bristol, then moved to London around 2000.

In 2003, at an exhibition called Turf War, held in a London warehouse, Banksy painted on animals. At the time he gave one of his very few interviews, to the BBC’s Nigel Wrench. Although the RSPCA declared the conditions suitable, an animal rights activist chained herself to the railings in protest. An example of his subverted paintings is Monet’s Water Lily Pond, adapted to include urban detritus such as litter and a shopping trolley floating in its reflective waters; another is Edward Hopper’s Nighthawks, redrawn to show that the characters are looking at a British football hooligan, dressed only in his Union Flag underpants, who has just thrown an object through the glass window of the cafe. These oil paintings were shown at a twelve-day exhibition in Westbourne Grove, London in 2005.

Banksy, along with Shepard Fairey, Dmote, and others, created work at a warehouse exhibition in Alexandria, Sydney, for Semi-Permanent in 2003. Approximately 1,500 people attended.

In August 2004, Banksy produced a quantity of spoof British £10 notes replacing the picture of the Queen’s head with Diana, Princess of Wales’s head and changing the text “Bank of England” to “Banksy of England”. Someone threw a large wad of these into a crowd at Notting Hill Carnival that year, which some recipients then tried to spend in local shops. These notes were also given with invitations to a Santa’s Ghetto exhibition by Pictures on Walls. The individual notes have since been selling on eBay. A wad of the notes was also thrown over a fence and into the crowd near the NME signing tent at the Reading Festival. A limited run of 50 signed posters containing ten uncut notes was also produced and sold by Pictures on Walls for £100 each to commemorate the death of Princess Diana. One of these sold in October 2007 at Bonhams auction house in London for £24,000.

In August 2005, Banksy, on a trip to the Palestinian territories, created nine images on the Israeli West Bank wall.

After Christina Aguilera bought an original of Queen Victoria as a lesbian and two prints for £25,000, on 19 October 2006, a set of Kate Moss paintings sold in Sotheby’s London for £50,400, setting an auction record for Banksy’s work. The six silk-screen prints, featuring the model painted in the style of Andy Warhol’s Marilyn Monroe pictures, sold for five times their estimated price. Their stencil of a green Mona Lisa with real paint dripping from her eyes sold for £57,600 at the same auction. In December, journalist Max Foster coined the phrase, “the Banksy effect”, to illustrate how interest in other street artists was growing on the back of Banksy’s success.

On 21 February 2007, Sotheby’s auction house in London auctioned three works, reaching the highest ever price for a Banksy work at auction: over £102,000 for Bombing Middle England. Two of his other graffiti works, Girl with Balloon and Bomb Hugger, sold for £37,200 and £31,200 respectively, which were well above their estimated prices. The following day’s auction saw a further three Banksy works reach soaring prices: Ballerina with Action Man Parts reached £96,000; Glory sold for £72,000; Untitled (2004) sold for £33,600; all significantly above price estimates. To coincide with the second day of auctions, Banksy updated his website with a new image of an auction house scene showing people bidding on a picture that said, “I Can’t Believe You Morons Actually Buy This Shit.”

In February 2007, the owners of a house with a Banksy mural on the side in Bristol decided to sell the house through Red Propeller art gallery after offers fell through because the prospective buyers wanted to remove the mural. It is listed as a mural that comes with a house attached.

In April 2007, Transport for London painted over Banksy’s image of a scene from Quentin Tarantino’s film Pulp Fiction (1994), featuring Samuel L. Jackson and John Travolta clutching bananas instead of guns. Although the image was very popular, Transport for London claimed that the graffiti created “a general atmosphere of neglect and social decay which in turn encourages crime” and their staff are “professional cleaners not professional art critics”. Banksy painted the same site again and, initially, the actors were portrayed as holding real guns instead of bananas, but they were adorned with banana costumes. Sometime later, Banksy made a tribute artwork over this second Pulp Fiction work. The tribute was for 19-year-old British graffiti artist Ozone who, along with fellow artist Wants, was hit by an underground train in Barking, east London on 12 January 2007. Banksy depicted an angel wearing a bullet-proof vest holding a skull. He also wrote a note on his website saying:

On 27 April 2007, a new record high for the sale of Banksy’s work was set with the auction of the work Space Girl and Bird fetching £288,000 (US$576,000) around 20 times the estimate at Bonhams of London. On 21 May 2007 Banksy gained the award for Art’s Greatest living Briton. Banksy, as expected, did not turn up to collect his award and continued with his anonymous status. On 4 June 2007, it was reported that Banksy’s The Drinker had been stolen. In October 2007, most of his works offered for sale at Bonhams auction house in London sold for more than twice their reserve price.

Also in March 2008, a stencilled graffiti work appeared on Thames Water tower in the middle of the Holland Park roundabout, and it was widely attributed to Banksy. It was of a child painting the tag “Take this—Society!” in bright orange. London Borough of Hammersmith and Fulham spokesman, Councillor Greg Smith branded the art as vandalism, and ordered its immediate removal, which was carried out by H&F council workmen within three days.

The Westminster City Council stated in October 2008 that the work One Nation Under CCTV, painted in April 2008 would be painted over as it was graffiti. The council said it would remove any graffiti, regardless of the reputation of its creator, and specifically stated that Banksy “has no more right to paint graffiti than a child”. Robert Davis, the chairman of the council planning committee told The Times newspaper: “If we condone this then we might as well say that any kid with a spray can is producing art.” The work was painted over in April 2009. In December 2008, The Little Diver, a Banksy image of a diver in a duffle coat in Melbourne, Australia, was destroyed. The image had been protected by a sheet of clear perspex; however, silver paint was poured behind the protective sheet and later tagged with the words “Banksy woz ere”. The image was almost completely obliterated.

In 2008, in Melbourne, paint was poured over a stencil of an old-fashioned diver wearing a trench coat. In April 2010, the Melbourne City Council reported that they had inadvertently ordered private contractors to paint over a rat descending in a parachute adorning the wall of an old council building behind the Forum Theatre.

In May 2009, Banksy parted company with agent Steve Lazarides and announced that Pest Control, the handling service who act on his behalf, would be the only point of sale for new works. On 13 June 2009, the Banksy vs Bristol Museum show opened at Bristol City Museum and Art Gallery, featuring more than 100 works of art, including animatronics and installations; it is his largest exhibition yet, featuring 78 new works. Reaction to the show was positive, with over 8,500 visitors to the show on the first weekend. Over the course of the twelve weeks, the exhibition was visited over 300,000 times. In September 2009, a Banksy work parodying the Royal Family was partially destroyed by Hackney Council after they served an enforcement notice for graffiti removal to the former address of the property owner. The mural had been commissioned for the 2003 Blur single “Crazy Beat” and the property owner, who had allowed it to be painted, was reported to have been in tears when she saw it was being painted over.

In December 2009, Banksy marked the end of the 2009 United Nations Climate Change Conference by painting four murals on global warming. One included the phrase, “I don’t believe in global warming;” the words were submerged in water. A feud and graffiti war between Banksy and King Robbo broke out when Banksy allegedly painted over one of Robbo’s tags. The feud has led to many of Banksy’s works being altered by graffiti writers.

In March 2010, a modified version of the work Forgive Us Our Trespassing–a kneeling boy with a spray-painted halo–was displayed at London Bridge Station on a poster. This version of the work did not possess the halo due to its stylistic nature and the prevalence of graffiti in the underground. After a few days the halo was repainted by a graffitist, so Transport for London disposed of the poster.

In April, to coincide with the premiere of Exit Through the Gift Shop in San Francisco, five of his works appeared in various parts of the city. Banksy reportedly paid a San Francisco Chinatown building owner $50 for the use of their wall for one of his stencils. In May 2010, seven new Banksy works of art appeared in Toronto, Canada, though most have been subsequently painted over or removed.

Many works that make up the Better Out Than In series in New York City have been defaced, some just hours after the piece was unveiled. At least one defacement was identified as done by a competing artist, OMAR NYC, who spray-painted over Banksy’s red mylar balloon piece in Red Hook. OMAR NYC also defaced some of Banksy’s work in May 2010.

In July 2011 one of Banksy’s early works, Gorilla in a Pink Mask, which had been a prominent landmark on the exterior wall of a former social club in Eastville for over ten years, was unwittingly painted over after the premises became a Muslim cultural centre.

In late January 2011, Exit Through the Gift Shop was nominated for a 2010 Oscar for Best Documentary Feature. Banksy released a statement about the nomination, stating, “This is a big surprise… I don’t agree with the concept of award ceremonies, but I’m prepared to make an exception for the ones I’m nominated for. The last time there was a naked man covered in gold paint in my house, it was me.” Leading up to the Oscars, Banksy blanketed Los Angeles with street art. Many people speculated if Banksy would show up at the Oscars in disguise and make a surprise appearance if he won the Oscar. Exit Through the Gift Shop did not win the award, which went to Inside Job. In early March 2011, Banksy responded to the Oscars with an artwork in Weston-super-Mare, UK, of a little girl holding the Oscar and pouting. Many people think that it is about 15-month-old Lara, who dropped and damaged her father’s (The King’s Speech co-producer Simon Egan) Oscar statue. Exit Through the Gift Shop was broadcast on British public television station Channel 4 on 13 August 2011.

Banksy was credited with the opening couch gag for the 2010 The Simpsons episode “MoneyBart”, depicting people working in deplorable conditions and using endangered or mythical animals to make both the episodes cel-by-cel and the merchandise connected with the program. His name appears several times throughout the episode’s opening sequence, spray-painted on assorted walls and signs. Fox sanitised parts of the opening “for taste” and to make it less grim. In January 2011, Banksy published the original storyboard on its website. According to Banksy, the storyboard “led to delays, disputes over broadcast standards and a threatened walkout by the animation department.” Executive director Al Jean jokingly said, “This is what you get when you outsource.”

In May 2011 Banksy released a lithographic print which showed a smoking petrol bomb contained in a ‘Tesco Value’ bottle. This followed a long-running campaign by locals against the opening of a Tesco Express supermarket in Banksy’s home city of Bristol. Violent clashes had taken place between police and demonstrators in the Stokes Croft area. Banksy produced the poster ostensibly to raise money for local groups in the Stokes Croft area and to raise money for the legal defense of those arrested during the riots. The posters were sold exclusively at the Bristol Anarchists Bookfair in Stokes Croft for £5 each.

In January 2011, he was nominated for the Academy Award for Best Documentary for Exit Through the Gift Shop. In 2014, he was awarded Person of the Year at the 2014 Webby Awards. In 2014, young adults from abroad named Banksy a British cultural icon in a list that included William Shakespeare, Queen Elizabeth II, David Beckham, The Beatles, Charlie Chaplin, J. K. Rowling, Elton John, and Adele.

On 1 October 2013, Banksy began a one-month “show on the streets of New York [City]”, for which he opened a separate website and granted an interview to The Village Voice via his publicist.

It was reported that then-New York City Mayor Michael Bloomberg called Banksy a vandal whose work is not the definition of art, and that the NYPD’s vandal squad was on the hunt for Banksy over his various graffiti art and installations. One creation was a fiberglass sculpture of Ronald McDonald and a real person, barefoot and in ragged clothes, shining the oversized shoes of Ronald McDonald. The sculpture was unveiled in Queens but moved outside a different McDonald’s around the city every day. Other works included a YouTube video showing what appears to be footage of jihadist militants shooting down an animated Dumbo; travelling installations that toured the city including a slaughterhouse delivery truck full of stuffed animals and a waterfall; and a modified painting donated to a charity shop which was later sold in an online auction for $615,000. Banksy also posted a mock-up of a New York Times op-ed attacking the design of the One World Trade Center after the Times rejected his submission. The residency in New York concluded on 31 October 2013; many of the pieces, though, were either vandalised, removed or stolen.

Some have criticised the “obviousness” of Banksy’s work and accused it of being “anarchy-lite” geared towards a middle class “hipster” audience. Much of this criticism came forward during his series of works in New York in 2013. Many New York street artists, such as TrustoCorp, criticised Banksy, and much of his work was defaced.

In October 2014, an internet hoax circulated that Banksy had been arrested and his identity revealed.

In February 2015 Banksy published a 2-minute video titled Make this the year YOU discover a new destination about his trip to Gaza Strip. During the visit he painted a few artworks including a kitten on the remains of a house destroyed by an Israeli air strike. (“I wanted to highlight the destruction in Gaza by posting photos on my website—but on the internet people only look at pictures of kittens”) and a swing hanging off a watchtower. In a statement to The New York Times his publicist said,

Banksy opened Dismaland, a large scale group show modelled on Disneyland on 21 August 2015. It lampooned the many disappointing temporary themed attractions in the UK at the time. Dismaland permanently closed on 27 September 2015. The “theme park” was located in Weston-super-Mare, United Kingdom. According to the Dismaland website, artists represented on the show include Damien Hirst and Jenny Holzer.

In December 2015, Banksy created several murals in the vicinity of Calais, France, including the so-called “Jungle” where migrants live as they attempt to enter the United Kingdom. One of the pieces, The Son of a Migrant from Syria, depicts Steve Jobs as a migrant.

In June 2017, DJ Goldie referred to Banksy as “Rob”.

In 2017, marking the 100th anniversary of the British control of Palestine, Banksy financed the creation of the Walled Off Hotel in Bethlehem. This hotel is open to the public and contains rooms designed by Banksy, Sami Musa, and Dominique Petrin, and each of the bedrooms face the wall. It also houses a contemporary art gallery.

During the 2017 United Kingdom general election, Banksy offered voters a free print if they cast a ballot against the Conservative candidates standing in the Bristol North West, Bristol West, North Somerset, Thornbury, Kingswood and Filton constituencies. According to a note posted on Banksy’s website, an emailed photo of a completed ballot paper showing it marked for a candidate other than the Conservative candidate would result in the voter being mailed a limited edition piece of Banksy art. On 5 June 2017 the Avon and Somerset Constabulary announced it had opened an investigation into Banksy for the suspected corrupt practice of bribery, and the following day Banksy withdrew the offer stating “I have been warned by the Electoral Commission that the free print offer will invalidate the election result. So I regret to announce that this ill-conceived and legally dubious promotion has now been cancelled.”

Banksy has donated a number of works to promote various causes, such as Civilian Drone Strike, which was sold in 2017 at £205,000 to raise funds for Campaign Against Arms Trade and Reprieve. It was part of the exhibition ‘Art the Arms Fair’ set up in opposition to the DSEI arms fair. In 2018, a sculpture titled Dream Boat, which was exhibited in Dismaland in 2015, was raffled off in aid of Help Refugees for a minimum donation of £2 for every guesses of its weight in a pop-up Choose Love shop in Carnaby Street. In 2002, he produced artwork for the Greenpeace campaign Save or Delete. He also provided works to support local causes; in 2013, a work titled The Banality of the Banality of Evil was sold for an undisclosed amount after a failed auction to support an anti-homelessness charity in New York, In 2014, an artwork on a doorway titled Mobile Lovers was sold £403,000 to keep a youth club in Bristol open, and he created merchandise for homeless charities in Bristol in 2019.

2018 saw Banksy return to New York five years after his Better Out Than In residency. A trademark rat running around the circumference of a clock-face, dubbed Rat race, was torn down by developers within a week of it appearing on a former bank building at 101 West 14th Street, but other works, including a mural of imprisoned Kurdish artist Zehra Doğan on the famed Bowery Wall and a series of others across Brooklyn, remain on display.

In October 2018, one of Banksy’s works, Balloon Girl, was sold in an auction at Sotheby’s in London for £1.04m. However, shortly after the gavel dropped and it was sold, an alarm sounded inside of the picture frame and the canvas passed through a shredder hidden within the frame, partially shredding the picture. Banksy then posted an image of the shredding on Instagram captioned “Going, going, gone…”. After the sale, the auction house acknowledged that the self-destruction of the work was a prank by the artist. The prank received wide news coverage around the world, with one newspaper stating that it was “quite possibly the biggest prank in art history.” Joey Syer, co-founder of an online platform facilitating art dealer sales, told the Evening Standard: “The auction result will only propel this further and given the media attention this stunt has received, the lucky buyer would see a great return on the £1.02M they paid last night, this is now part of art history in its shredded state and we’d estimate Banksy has added at a minimum 50% to its value, possibly as high as being worth £2m+.” A man seen filming the shredding of the picture during its auction has been suggested to be Banksy. Banksy has since released a video on how the shredder was installed into the frame and the shredding of the picture, explaining that he had surreptitiously fitted the painting with the shredder a few years previously, in case it ever went up for auction. To explain his rationale for destroying his own artwork, Banksy quoted Picasso: “The urge to destroy is also a creative urge”. (Although Banksy cited Picasso, this quote is usually attributed to Mikhail Bakunin.) It is not known how the shredder was activated. Banksy has released another video indicating that the painting was intended to be shredded completely. The video shows a sample painting completely shredded by the frame and says: “In rehearsals it worked every time…”.

In 2018, Banksy created a piece live, as it was being auctioned. The piece, titled, Love is in the Bin, was originally the painting, Girl with Balloon, before it was shredded at Sotheby’s. While the bidding was going on, a shredder was activated from within the frame, and the piece was partially shredded, thus creating a new piece.

A two-sided graffiti piece, one side depicting a child tasting the falling snow, the other revealing that the snow is in fact smoke and embers from a fire, appeared on two walls of a steelworker’s garage in Port Talbot in December. Banksy then revealed that the painting was in fact his via an Instagram video soundtracked by the festive children’s song ‘Little Snowflake’. Many fans of the artist went to see the painting and Plaid Cymru councillor for Aberavon, Nigel Thomas Hunt, stated that the town was “buzzing” with speculation that the work was Banksy’s. The owner of the garage, Ian Lewis, said that he had lost sleep over fears that the image would be vandalised. A plastic screen, partially funded by Michael Sheen, was installed to protect the mural, but was attacked by a “drunk halfwit”. Extra security guards were subsequently drafted to protect the graffiti piece. In May 2019, the mural was moved to a gallery in the town’s Ty’r Orsaf building.

On 4 October 2019, greetings cards distributor Full Colour Black publicly revealed itself as the company involved in the trademark dispute whilst rejecting Banksy’s claims as “entirely untrue”. The company claimed it had contacted Banksy’s lawyers several times to offer to pay royalties.

In October 2019, Devolved Parliament, a 2009 painting by Banksy showing Members of Parliament depicted as chimpanzees in the House of Commons, sold at Sotheby’s in London for just under £9.9 million. On Instagram, the artist said it was a “record price for a Banksy painting” and “shame I didn’t still own it”. At 13 feet (4.0 m) wide it is Banksy’s biggest known work on canvas. The auction house stated: “Regardless of where you sit in the Brexit debate, there’s no doubt that this work is more pertinent now than it has ever been.”

On 13 February 2020, the Valentine’s Banksy mural appeared on the side of a building in Bristol’s Barton Hill neighbourhood, depicting a young girl firing a slingshot of real red flowers and leaves. In the early hours of Valentine’s Day (14 February), Banksy confirmed this was his work on his Instagram account and website. The painting was defaced just days after appearing. He dedicated a painting to healthcare workers and donated it to the University Hospital of Southampton during the global coronavirus pandemic in May 2020.

Banksy has been producing a number of works and projects in support of the Palestinians since the mid-2000s, including The Walled Off Hotel in Bethlehem. In July 2020, Banksy sold three paintings forming a triptych titled Mediterranean Sea View 2017, which raised £2.2 million for a hospital in Bethlehem. The paintings were original created for The Walled Off Hotel, and are Romantic-era paintings of the seashore that have been modified with images of lifebuoys and orange life jackets washed up on the shore, a reference to the European migrant crisis.

Banksy gifted a painting titled Game Changer to a hospital in May 2020 as a tribute to National Health Service workers during the COVID-19 pandemic.

In August 2020, it was revealed that Banksy had privately funded a rescue boat to save refugees at risk in the Mediterranean Sea. The former French Navy boat, renamed after Louise Michel, has been painted pink with an image of a young girl holding a heart-shaped safety float.