Hoerle was born in Cologne. He studied at the Cologne School of Arts and Crafts but was mostly self-taught as an artist. After military service in World War I he met Franz Wilhelm Seiwert in 1919 and worked with him on the journal Ventilator. Together with his wife Angelika (1899–1923), Hoerle became active in the Cologne Dada scene. He co-founded the artists' group Stupid, and in 1920 he published the Krüppelmappe (Cripples Portfolio). Hoerle's work retained a certain dour absurdism after he adopted a figurative constructivist style influenced by the RussiansVladimir Tatlin and El Lissitzky and by the Dutch movement De Stijl. His paintings feature generic-looking figures, presented in strict profile or in stiff, frontal poses.
In 1929 he began publication of "a-z", the journal of the Cologne Progressives art group. He was among the many German artists whose works were condemned as degenerate art when the Nazis took power in 1933. He died in Cologne in 1936.