Jean Dewasne was born in Lille, France on May 21, 1921. During his youth, he studied music, but began exploring the art of painting at the age of 12. Dewasne spent two years studying architecture, during which he became familiar with the major classical buildings. He entered the "Ecole des Beaux Arts" of Paris, however, he quickly abandoned his studies to devote himself entirely to painting. In 1941, he exhibited for the first time, but it was not until 1942 that his first abstract painting appeared. During the same year, he had his first solo exhibition. 
In 1945, Dewasne joined a circle of artists including Deyrolle, Hartung, Marie Raymond and Schneider that launched a campaign in support of abstract art. Their exposition in February of 1946, curated by René de Solier, revealed a type of abstract art that had new forms and came from rich and varied trends. Later on, Poliakoff also became a part of this group. In 1946, Dewasne was chosen for the newly founded Kandinsky prize. During the same year, he contributed to the founding of the "Salon des Réalitées" and was elected a member of its committee, along with Sonia Delaunay, Jean Arp, Pevsner, Gorin, and others. 
During this period, Dewasne utilized the chiaroscuro technique in his painting, however, in 1947, he began to include ragged forms in vivid colors. In 1948, he completed his first large mural, “La gioia di vivere.” In 1950, Dewasne founded "L'Atelier d'Art Abstrait," and for three years, in a room in front of the Church of St. Germain des Prés, he organized "Conférences d'Art Abstrait." The Conférences provided a free and open environment to debate and exchange opinions, and they were attended by everyone from artists to critics to specialists in diverse fields, including everything from physics to psychology. In these years, the theory of connections between dialectical logic and abstract art, a theory to which Dewasne attributed great importance, developed. 
In 1952, he completed the first “anti-sculture”, in which industrial and anonymous, unresearched objects, or simple plastic sense created by the artist became real and true works of art. Then, Dewasne began an intense period of travel throughout Europe and America where he held exhibitions and conferences. In 1966, his first retrospective exhibition took place at the Kunsthalle of Berne. He represented France in 1968 at the Biennale di Venezia, and in 1972, he exhibited in the United States at the Lefebvre gallery. Between 1974 and 1975, two important solo exhibitions took place, one at the Louisiana Museum in Humblebaek and the other at the Museum of Art in Pittsburgh. In 1979, another solo exhibition was held abroad at the Museo d'Arte contemporanea of Caracas. During the 1980s, he participated in two group exhibitions at the Centre Georges Pompidou-- first Paris-Paris, 1937-1957 in 1981 and then Les Années 50 in 1988. Between 1985 and 1989, Dewasne completed two large murals, measuring 100 meters tall and 70 meters long, at the Arche de le Défense in Paris. In 1991, he was elected a member of the Académie de Peinture all'Institut de France. In addition, Dewasne explored other fields, writing numerous articles on different topics, illustrating books, stage designing for theatrical productions, and writing poems. 
Jean Dewasne died July 23, 1999.