Otto Muehl (16 June 1925 – 26 May 2013) was an Austrian artist and convicted sex criminal, who was known as one of the co-founders as well as a main participant of Viennese Actionism and for founding the Friedrichshof Commune.

[1] After the war, he studied teaching German and History, and Pedagogy of Art at the Wiener Akademie der bildenden Künste.

[4] He made rhizomatic structures with scrap iron ("Gerümpelplastiken"), but soon proceeded to the "Aktion" in the vein of the New York Happenings.

The declared aim was the destruction of bourgeois marriage and private property, free love, and collective education of the children.

He required members to crush the "body armor" (after Wilhelm Reich)[clarification needed] and in some individual cases he experimented with the so-called “Watschenanalyse” ("slapping analysis").

He became a painter in the expressionist style, and held regular lessons on painting for his communards in his Friedrichshof commune.

While serving prison time for the sexual abuse of minors, Muehl continued to be artistically engaged: he painted around 300 pictures and wrote about art theory.

In 2010 Muehl celebrated his 85th birthday, on this occasion the Leopold Museum in Vienna showed an extensive exhibition of his late work.