Hockney was born in Bradford and educated at Bradford Grammar School, Bradford College of Art and the Royal College of Art in London where he met R. B. Kitaj. While still at the Royal College of Art Hockney was featured in the exhibition Young Contemporaries alongside Peter Blake that announced the arrival of British Pop Art. He became associated with pop art, but his early works also display expressionist elements, not dissimilar to certain works by Francis Bacon. Sometimes, as in We Two Boys Together Clinging (1961), named after a poem by Walt Whitman, these works make reference to his homosexuality. From 1963 Hockney was represented by the influential art dealer John Kasmin.

In 1963 Hockney visited New York making contact with Andy Warhol. Later, a visit to California, where he settled, inspired Hockney to make a series of oil paintings of swimming pools in Los Angeles. These are executed in a more realistic style and use vibrant colours. He also made prints, portraits of friends, and stage designs for the Royal Court Theatre, Glyndebourne, La Scala and the Metropolitan Opera in New York City.

Hockney studied lithography in art school in Bradford, Yorkshire. His first print was Myself and My Heroes (1961), where he appears beside a haloed Gandhi and Walt Whitman. His first major project in printmaking was a series of sixteen etchings where he represents Hogarth's Rake's Progress autobiographically. In the 1960s in California, he created with Ken Tyler another series of prints titled A Hollywood Collection. Many of his lithographs are portraits of his friends, most frequently of them Celia Birtwell. In 1970-1 Hockney painted Mr and Mrs Clarke with Percy a double portrait of Celia Birtwell and her then husband the fashion designer Ossie Clarke in their Notting Hill home. The painting has become one of the most popular in the collection of the Tate Gallery and was voted as one of the UK's favourite paintings. His first prints during the 1980s were two large lithographs of Celia published by Gemini G.E.L. (the studio started by Ken Tyler) in 1982. Hockney also made two etchings honoring Pablo Picasso, whose work he admired and was influenced by, after Picasso's death in 1973.

In an unusual use of paintings, the opening credits of the 1978 Neil Simon film, California Suite, based on his play of the same name, show a tasteful and leisurely display of about a dozen unobscured California-themed Hockney paintings.

Hockney also worked with photography, or more precisely - photocollaging. Using varying numbers (~5-150) of small polaroid snaps or photolab-prints of a single subject Hockney arranged a patchwork to make a composite image. Because these photos are taken from different perspectives and at slightly different times, the result is work which has an affinity with cubism, affinity which was some of Hockney's major aims - discussing the way human vision works. Some of these pieces are landscapes such as Pearblossom Highway #2, others being portraits.

These photographic collages appeared mostly in his works between 1970 and 1986. He referred to them as "joiners". He began this style of art by taking polaroid photographs of one subject and arranging them into a grid layout. The subject would actually move while being photographed so that the piece would show the movements of the subject seen from the photographer's perspective. In later works Hockney changed his technique and moved the camera around the subject instead.

Hockney's creation of the joiners were never planned, he just sort of discovered them. He noticed in the late sixties that photographers were using cameras with wide-angle lenses to take pictures. He didn't like them because the photographs were distorted in ways that a person never sees. It was not consistent with human vision. He was working on a painting of a living room in Los Angeles in which the living room and terrace were combined into one picture at the time. He took polaroid shots of the living room and glued them together, not intending for them to be a composition on their own. Upon looking at the final composition, he realized it created a narrative as if the viewer was moving through the room. He began to work more and more with photography after this discovery and even stopped painting for a period of time to pursue this new style of photography.

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

Another important commission of his was to draw with the Quantel Paintbox, a computer program that allowed the artist to sketch direct onto the monitor screen. This commission was taken by Hockney in December 1985. Using this program was similar to drawing on the PET film for prints which he had much experience in. His works were so successful that a video was made while he was using the Quantel and broadcast by the BBC. His work with the Quantel showed him that new technology could be used for art.

In the 2001 television programme and book, Secret Knowledge, Hockney posited that the Old Masters had used the camera lucida, a series of lenses or mirrors, to project an image of their models onto the canvas, which they had then traced around, enabling them to achieve very high levels of realism. His hypothesis is rejected by almost all serious optical historians. As Ingrid Rowland wrote in the New York Review of Books, "He and Charles Falco have become true believers in a world that is to a great extent of their own making."

In 1974, Hockney was the subject of Jack Hazan's film, A Bigger Splash (named after one of Hockney's swimming pool paintings from 1967). Hockney was made a Companion of Honour in 1997 and is also a Royal Academician. Many of Hockney's works are now housed in the old mill Salts Mill in Saltaire, near his home town of Bradford.

His A Bigger Grand Canyon, a series of 60 paintings which combined to produce one enormous picture, was bought by the National Gallery of Australia for $4.6 million.

In September 2005 he declared his opposition to the proposed UK ban on smoking in public places.