George Stillman, painter, printmaker, photographer, and teacher, was born to Stella and Herman Stillman in Laramie, Wyoming on 25 February 1921. In 1922, the Stillman family was living in Los Angeles and, by 1930, they had settled in Ontario, California. His precocious curiosity was nurtured by his father, a professional photographer, who allowed him to experiment in his photographic darkroom. At seventeen, Stillman submitted work for the 1939 Golden Gate International Exposition, which won first prize for creative photography.

Stillman attended Chaffey College in Alta Loma, California in 1941 and then enrolled in the University of California Berkeley where he studied chemistry. The U.S. entry into World War II interrupted his studies as he was drafted into military service in 1942.

After his discharge in 1945, Stillman opened a commercial photography studio and enrolled in the California School of Fine Arts (CSFA) under the G.I. Bill. He began to paint and made his first original prints in the lithography class taught by Ray Bertrand at the CSFA. As he was exploring abstraction, he made friends with fellow artists Walt Kuhlman, James Budd Dixon, Frank Lobdell, Richard Diebendorn, and John Hultburg. The six artists became known as the Sausalito Six as some of the artists had studios in the Industrial Center Building, a converted wartime building, in Sausalito. They exhibited at the Seashore Gallery of Modern Art in Sausalito and, in an effort to support their gallery, the six produced the portfolio Drawings in 1948. The portfolio consisted of seventeen Abstract Expressionist offset lithographs that were printed by Eric Ledin in Mill Valley. Drawings has become recognized as the first Abstract Expressionist portfolio created in the U.S.

In 1949, Stillman won the Ann Bremer award from the San Francisco Museum of Art and the Samuel S. Bender Award which he used to study in Mexico. Stillman's work was shown in galleries in Guadalajara and Mexico City in 1951 and, that year, he accepted a teaching position at the University of Guadalajara. In 1953, Stillman began working for the U.S. Army in Latin America as chief of the Reproduction Branch and he taught photolithography. He also worked for the Army in Brazil and Bolivia.

Stillman returned to the United States in 1955 and accepted the position of producer-director at Arizona State University Television in Tempe. While working at the university he attended classes and received his B.F.A. in 1968 and his M.F.A. in 1970. That same year, he was invited to join the faculty of Columbus College in Georgia where he established the art department. In 1972, Stillman moved to Washington state where he taught at Central Washington State University until his retirement in 1988. Stillman received the National Endowment for the Art Fellowship Award in 1990.

George Stillman is represented in the collections of the Nora Eccles Harrison Museum of Art, Utah State University, Logan; the British Museum, London; the Oakland Museum of California; the Metropolitan Museum of Art and the Whitney Museum of American Art, New York; the San Francisco Museum of Modern Art, California; the National Gallery of Art and the Smithsonian American Art Museum, Washington, D.C.; and the Worcester Art Museum, Massachusetts.

George Stillman died in Ellensburg, Washington on 12 March 1997.