Hockney was born in Bradford, England, to Laura and Kenneth Hockney (a conscientious objector in the Second World War), the fourth of five children. He was educated at Wellington Primary School, Bradford Grammar School, Bradford College of Art (where his teachers included Frank Lisle) and the Royal College of Art in London, where he met R. B. Kitaj. While there, Hockney said he felt at home and took pride in his work. At the Royal College of Art, Hockney featured in the exhibitionYoung Contemporaries—alongside Peter Blake—that announced the arrival of British Pop art. He was associated with the movement, but his early works displayexpressionist elements, similar to some works by Francis Bacon. When the RCA said it would not let him graduate in 1962, Hockney drew the sketch The Diploma in protest. He had refused to write an essay required for the final examination, saying he should be assessed solely on his artworks. Recognising his talent and growing reputation, the RCA changed its regulations and awarded the diploma.

On the morning of 18 March 2013, Hockney's 23-year-old assistant, Dominic Elliott, died as a result of drinking drain cleaner at Hockney's Bridlington studio; he had also earlier drunk alcohol and taken cocaine, ecstasy and temazepam. Elliott was a first- and second-team player for Bridlington rugby club. It was reported that Hockney's partner drove Elliott to Scarborough General Hospital where he later died. The inquest returned a verdict of death by misadventure and Hockney was never implicated.

In November 2015 Hockney sold his house in Bridlington, a five-bedroomed former guesthouse, for £625,000, cutting all his remaining ties with the town. He retains a studio in London and a house in Malibu, California.  Hockney has smoked cigarettes for over 60 years but has been teetotal since 1990 when he had a heart-attack. He holds a California Medical Marijuana Verification Card, which enables him to buy cannabis for medical purposes. He has used hearing aids since 1979, but realised he was going deaf long before that. He swims for half an hour each day and can stand for six hours at the easel.

Hockney made prints, portraits of friends, and stage designs for the Royal Court Theatre, Glyndebourne, La Scala and the Metropolitan Opera in New York City. Born with synaesthesia, he sees synesthetic colours in response to musical stimuli. This does not show up in his painting or photography artwork, but is a common underlying principle in his designs for stage sets for ballet and opera—where he bases background colours and lighting on the colours he sees while listening to the piece's music.

Hockney painted portraits at different periods in his career. From 1968, and for the next few years he painted friends, lovers, and relatives just under lifesize and in pictures that depicted good likenesses of his subjects. Hockney's own presence is often implied, since the lines of perspective converge to suggest the artist's point of view. Hockney has repeatedly returned to the same subjects - his parents, artist Mo McDermott (Mo McDermott, 1976), various writers he has known, fashion designers Celia Birtwell and Ossie Clark (Mr and Mrs Clark and Percy, 1970–71), curator Henry Geldzahler, art dealer Nicholas Wilder, George Lawson and his ballet dancer lover, Wayne Sleep.

On arrival in California, Hockney changed from oil to acrylic paint, applying it as smooth flat and brilliant colour. In 1965, the print workshop Gemini G.E.L. approached him to create a series of lithographs with a Los Angeles theme. Hockney responded by creating a ready-made art collection.

In the early 1980s, Hockney began to produce photo collages, which he called "joiners", first using Polaroid prints and subsequently 35mm, commercially processed colour prints. Using Polaroid snaps or photolab-prints of a single subject, Hockney arranged a patchwork to make a composite image. An early photomontage was of his mother. Because the photographs are taken from different perspectives and at slightly different times, the result is work that has an affinity withCubism, one of Hockney's major aims—discussing the way human vision works. Some pieces are landscapes, such asPearblossom Highway #2, others portraits, such as Kasmin 1982, and My Mother, Bolton Abbey, 1982.

Creation of the "joiners" occurred accidentally. He noticed in the late sixties that photographers were using cameras with wide-angle lenses. He did not like these photographs because they looked somewhat distorted. While working on a painting of a living room and terrace in Los Angeles, he took Polaroid shots of the living room and glued them together, not intending for them to be a composition on their own. On looking at the final composition, he realized it created a narrative, as if the viewer moved through the room. He began to work more with photography after this discovery and stopped painting for a while to exclusively pursue this new technique. Frustrated with the limitations of photography and its 'one eyed' approach, however, he returned to painting.

In 1976, at Atelier Crommelynck, Hockney created a portfolio of 20 etchings, The Blue Guitar: Etchings By David Hockney Who Was Inspired By Wallace Stevens Who Was Inspired By Pablo Picasso. The etchings refer to themes in a poem by Wallace Stevens, "The Man With The Blue Guitar". It was published by Petersburg Press in October 1977. That year, Petersburg also published a book, in which the images were accompanied by the poem's text.

Hockney was commissioned to design the cover and pages for the December 1985 issue of the French edition of Vogue. Consistent with his interest in cubism and admiration for Pablo Picasso, Hockney chose to paint Celia Birtwell (who appears in several of his works) from different views, as if the eye had scanned her face diagonally.

In December 1985, Hockney used the Quantel Paintbox, a computer program that allowed the artist to sketch directly onto the screen. Using the program was similar to drawing on the PET film for prints, with which he had much experience. The resulting work was featured in a BBC series that profiled a number of artists.

His artwork was used on the cover of the 1989 British Telecom telephone directory for Bradford.

Hockney returned more frequently to Yorkshire in the 1990s, usually every three months, to visit his mother who died in 1999. He rarely stayed for more than two weeks until 1997, when his friend Jonathan Silver who was terminally ill encouraged him to capture the local surroundings. He did this at first with paintings based on memory, some from his boyhood. Hockney returned to Yorkshire for longer and longer stays, and by 2005 was painting the countryside en plein air. He set up residence and an immense redbrick seaside studio, a converted industrial workspace, in the seaside town of Bridlington, about 75 miles from where he was born.The oil paintings he produced after 2005 were influenced by his intensive studies in watercolour (for over a year in 2003–2004). He created paintings made of multiple smaller canvases—nine, 15 or more—placed together. To help him visualize work at that scale, he used digital photographic reproductions; each day's work was photographed, and Hockney generally took a photographic print home.

In June 2007, Hockney's largest painting, Bigger Trees Near Warter, which measures 15 feet by 40 feet, was hung in the Royal Academy's largest gallery in its annualSummer Exhibition.

This work "is a monumental-scale view of a coppice in Hockney's native Yorkshire, between Bridlington and York. It was painted on 50 individual canvases, mostly working in situ, over five weeks last winter." In 2008, he donated it to the Tate Gallery in London, saying: "I thought if I'm going to give something to the Tate I want to give them something really good. It's going to be here for a while. I don't want to give things I'm not too proud of ... I thought this was a good painting because it's of England ... it seems like a good thing to do." The painting was the subject of a BBC1 Imagine film documentary by Bruno Wollheim called David Hockney: A Bigger Picture' (2009) which followed Hockney as he worked outdoors over the preceding two years.

Since 2009, Hockney has painted hundreds of portraits, still lifes and landscapes using the Brushes iPhone and iPad application, often sending them to his friends. His show Fleurs fraîches (Fresh flowers) was held at La Fondation Pierre Bergé in Paris. A Fresh-Flowers exhibit opened in 2011 at the Royal Ontario Museum in Toronto, featuring more than 100 of his drawings on 25 iPads and 20 iPods. In late 2011, Hockney revisited California to paint Yosemite National Park on his iPad. For the season 2012–2013 in the Vienna State Opera he designed, on his iPad, a large scale picture (176 sqm) as part of the exhibition series Safety Curtain, conceived by museum in progress.

In September 2016 Hockney announced the issue of a new book David Hockney: A Bigger Book, scheduled to be published in October by Benedikt Taschen and costing £1,750 (£3,500 with an added loose print). The book, weighing almost 70lbs, had gone through 19 proof stages.