Alfred Flechtheim ( 1878 – 1937) was a German art dealer and collector, journalist and publisher, and an important promoter and sponsor of avantgardist art during the Weimar Republic.
Born into a Jewish merchant family; Flechtheim first worked in his father's company after completing business internships in London and Paris. He made his first appearance as an art dealer with a collection of paintings by outstanding artists, among them Picasso, Cézanne, van Gogh, Braque, Kandinsky and Macke. Flechtheim opened several galleries in Germany and Austria, and founded the cultural magazine "Der Querschnitt" ('The Cross Section'.) After the Nazis confiscated part of his galleries and collections in the 1930s, he fled to Paris and later emigrated to New York. He died in London in 1937.