American artist who is sometimes considered the first of the Abstract Expressionists (Abstract Expressionism). Still painted large abstract canvases meant to evoke the mystery of human existence through pure colour and form. Like many other Abstract Expressionists, Still saw the act of painting as a heroic assertion of being and freedom in an age still recovering from the impact of World War II (1939–45).

Still was interested in art even as a child. While in high school, he was awarded an art scholarship to Spokane University in Washington, from which he graduated in 1933. His style had evolved from a type of regionalism to a presentation of a Western landscape that was dominated by gigantic figures and enigmatic rock formations. Gradually the pictorial elements in his pictures became more abstract, although they always retained their organic shapes and colours. After eight years of teaching at Washington State College (now Washington State University) in Pullman, Still moved to California, where he worked in the shipbuilding and aircraft industries during the war years. He taught at the Richmond (Va.) Professional Institute (now Virginia Commonwealth University) in 1943–45 and lived for a year in New York City. Returning to California in 1946, he taught at the California School of Fine Arts (now the San Francisco Art Institute), where he stayed until 1950. He lived again for a time in New York City and in 1961 acquired a 22-acre (9-hectare) farm near Westminster, Md., where he kept a studio until his death.

Still's mature paintings from the late 1940s on consist of interlocking jagged shapes in a dense, much-worked surface that he applied with a palette knife. He gradually increased the size of the shapes and also the size of his canvases, intending the large indeterminate space of the picture to envelop viewers in a field of sublime sensation. Still was interested in conveying awe before the unknowable—the sublime—that so many artists throughout history have sought to evoke. His work influenced many artists, including Jackson Pollock (Pollock, Jackson), Mark Rothko (Rothko, Mark), and Barnett Newman (Newman, Barnett), as well as other colour-field painters (colour-field painting).

Distrustful of dealers, collectors, and curators, Still bequeathed only two bodies of work—one to the Albright-Knox Gallery in Buffalo in 1964 and the other to the San Francisco Museum of Modern Art in 1975. In his will, he stipulated that the remainder of his estate, which constituted more than 2,000 works at his death, would be available to the public in any American city that devoted a museum exclusively to his art. The city of Denver eventually accepted the challenge, and the Clyfford Still Museum was scheduled to open there in 2010, 30 years after Still's death.