Rudolph Weisenborn (1881-1974) was an American Modernist painter. Born to German parents but orphaned at age nine, Weisenborn lived an itinerant life, taken in by a farming family and working odd jobs. He first attended the University of North Dakota in 1898, then the Students School of Art in Denver. Weisenborn rebelled against his academic art instruction, and became inspired by an exhibition of Impressionist art. Around 1912, he settled in Chicago and worked as a window designer for Marshall Field�s. He found further inspiration from the French avant-garde, specifically the proto-Cubist work of Paul Cezanne.

Weisenborn�s large-scale painting, Chicago (1928), is credited as the first abstract painting to be shown at the Art Institute of Chicago, and garnered ample press coverage. He created the only abstract mural for the 1933 Century of Progress Exhibition in Chicago and also worked for the Federal Arts Project in the Easel Division. In 1945, Chicago businessman Herman Spertus commissioned Weisenborn to paint the mural The Fighting Navy for the Great Lakes Naval Training Station.

Weisenborn was a leader in championing abstract art. He is well known as the founder of the Chicago No-Jury Society of Artists. The group was founded because many artists could not get their work accepted into the mainstream Art Institute shows. Weisenborn was also involved and helped found other radical artists groups such as the Salon des Refuses, Cor Ardens, and Neo-Arlimusic. In 1936, he helped found the New York-based American Abstract Artist�s Group. Weisenborn taught at Hull House (1920), the Chicago Academy of Fine Arts (1922-34), his own Weisenborn Art School (1934-64), and the Austin, Oak Park, River Forest Art League in Oak Park (1941).