The youngest of five sons, Pollock was born in Cody, Wyoming, and grew up in Arizona and California, attending Los Angeles' Manual Arts High School before being expelled for fighting and other disruptive behavior. He moved to New York City in 1930, following his brother, Charles Pollock, where they both studied under Thomas Hart Benton at the Art Students League. Benton's influence on Pollock's formative work can be seen in his use of curvilinear undulating rhythms and in the use of rural American subject matter.

Pollock's early representational work was influenced by the Mexican Muralists Siqueiros, Orozco, and Rivera - and even worked in Siqueiros's experimental workshop in 1936. After visiting exhibitions of Picasso and Surrealist Art, his work became increasingly symbolic. He traveled widely throughout the United States during the 1930's, but he settled in New York in 1934 where he worked on the WPA Federal Art Project from 1935 to 1942. Pollock's first solo show was held at the Peggy Guggenheim Art of this Century gallery in New York in 1943.

Pollock had for several years been in psychotherapy to try to cope with depression and this gave him an interest in Carl Jung's theory of primitive archetypes that formed the basis of his work between 1938 and 1944. These works were often violent and were not well received at first.

In 1944 Pollock married his long-term lover Lee Krasner and in 1945 they moved to The Springs, in East Hampton, Long Island New York. The Springs was a large country house, with a barn that Pollock eventually made into a studio. Pollock's style changed dramatically in 1947. He began painting with his (often very large) canvases on the floor, and developed what was called his "drip" (or his preferred term, "pour") technique. He used his brushes as implements for dripping paint, and the brush never touched the canvas. Pollock's technique of pouring and dripping paint is thought to be one of the origins of the term Action Painting. In the process of making paintings in this way he moved away from figurative representation, and challenged the Western tradition of using easel and brush, as well as moving away from use only of the hand and wrist - as he used his whole body to paint. Pollock was dubbed "Jack the Dripper" as a result of his painting style.

The change in style and technique probably came about as a result of many diverse influences. In the winter of 1947-48, Pollock published a commentary in an avant-garde periodical, called Possibilities, addressing his new method:

"My painting does not come from the easel. I hardly ever stretch the canvas before painting. I prefer to tack the unstretched canvas to the hard wall or the floor. I need the resistance of a hard surface. On the floor I am more at ease. I feel nearer, more part of the painting, since this way I can walk around it, work from the four sides and literally be in the painting." This is akin to the method of the Indian sand painters of the West.

"I continue to get further away from the usual painter's tools such as easel, palette, brushes, etc. I prefer sticks, trowels, knives and dripping fluid paint or a heavy impasto with sand, broken glass or other foreign matter added.

"When I am in my painting, I'm not aware of what I'm doing. It is only after a sort of 'get acquainted' period that I see what I have been about. I have no fear of making changes, destroying the image, etc., because the painting has a life of its own. I try to let it come through. It is only when I lose contact with the painting that the result is a mess. Otherwise there is pure harmony, an easy give and take, and the painting comes out well."

Pollock did observe Indian Sand Painting demonstrations at the Museum of Modern Art in the 1940's; he may have also seen Indian sand-painters on his trips to the West, although that is debated. Other influences on his "pour" technique include the Mexican muralists mentioned above, and also Surrealist automatism. Pollock denied "the accident"; he usually had an idea of how he wanted a particular piece to appear. It was about the movement of his body, over which he had control, mixed with the viscous flow of paint, the force of gravity, and the way paint was absorbed into the canvas. The mix of the uncontrollable and the controllable. Flinging, dripping, pouring, spattering, he would energetically move around the canvas, almost as if in a dance, and would not stop until he saw what he wanted to see.

Hans Namuth was a young photography student in 1950, and he was intrigued by what he called the "difficulty" of Pollock's allover abstractions. Namuth wanted to photograph and film Pollock at work, painting. Pollock promised to start a new painting especially for the photographic session, but when Namuth arrived, Pollock apologized and told him the painting was finished. Namuth's comment upon entering the studio:

"A dripping wet canvas covered the entire floor. . . . There was complete silence. . . . Pollock looked at the painting. Then, unexpectedly, he picked up can and paint brush and started to move around the canvas. It was as if he suddenly realized the painting was not finished. His movements, slow at first, gradually became faster and more dancelike as he flung black, white, and rust colored paint onto the canvas. He completely forgot that Lee and I were there; he did not seem to hear the click of the camera shutter. . . My photography session lasted as long as he kept painting, perhaps half an hour. In all that time, Pollock did not stop. How could one keep up this level of activity? Finally, he said 'This is it.'" His account of this shows a man completely absorbed in the act of creation.

When the first set of these paintings was exhibited at the Betty Parsons Gallery in 1948 it was a sensation and a sell out. Pollock was able to take on a larger studio building and there produced the series of 6 paintings of 1950 for which he is most renowned. Pollock was profiled in Time Magazine as 'the greatest living American artist' in 1951.

From 1938 to 1942 he worked for the Federal Art Project; in the 1950s, Pollock was supported by the CIA via the Congress for Cultural Freedom (CCF).

Pollock's work after 1951 was darker in colour, often only black, and began to reintroduce figurative elements. Pollock had moved to a more commercial gallery and there was great demand from collectors for new paintings. In response to this pressure his alcoholism deepened.

Pollock's career was cut short when he died in an alcohol-related, single car crash in 1956 at the age of only 44, killing one of his passengers, Edith Metzger. The other passenger in the Cadillac convertible, his girlfriend Ruth Kligman, survived. After his death, Pollock's gallery sold all the works left in his studio including many works that he had not intended to release.

His 1952 painting of Blue Poles was sold for $2 million, which was then the highest price paid for a contemporary artwork, when it was bought by the National Gallery of Australia in 1973.

He was the subject of the documentaries Jackson Pollock (1987) and Jackson Pollock - Love & Death on Long Island (1999) as well as a movie drama called Pollock (2000) starring Ed Harris. An earlier ten-minute documentary Jackson Pollock (1951) was directed by Hans Namuth and had music by Morton Feldman.