George Eugene Ernest Johanson, Jr., was born in Seattle, the oldest of three children of parents of Scandinavian descent. As a child, he was skilled at drawing; and in 1946, at the age of seventeen, he enrolled at Portland's Museum Art School (now the Pacific Northwest College of Art). Though he later spent time in New York, Mexico, and London, Portland has remained Johanson's home and imaginative center.

When Johanson arrived at the Museum School, the locus of modern art was shifting from Paris to New York. His instructors William Givler, Louis Bunce, and Jack McLarty alerted him to developments in New York and urged him to spend time there. They also offered him alternative approaches to the Abstract Expressionist painting of the New York School. Johanson spent 1950-1953 in New York studying printmaking and meeting such well-known artists as Willem De Kooning.

Johanson's distinctive style fully emerged in the 1970s with such works as Black Rabbit's Red Room (1978; Hallie Ford Museum of Art), in which portraits of his artist friends Bunce, McLarty, and Manuel Izquierdo are combined with self-portraits and images of his parents, all overseen by a rabbit perched on a table. Bold color, strong patterns, and imagery that indexes Johanson's life are characteristic of his mature work. His highly original art contains references to Renaissance art, German Expressionism, Surrealism, the New York School, British painting of the 1960s, and the work of Portland artists such as Bunce, McLarty, and James McGarrell.

Paintings by Johanson are in the Smithsonian American Art Museum, the Seattle Art Museum, the Portland Art Museum, the Jordan Schnitzer Museum of Art (University of Oregon), the Hallie Ford Museum of Art (Willamette University), and numerous other public, corporate, and private collections. Johanson died of heart failure in October 2022.