Oswald Tschirtner (1920, Perchtoldsdorf - 20 May 2007, Maria-Gugging) was an Austrian mentally ill outsider artist known for his minimalist (naivist, possibly?) drawings. He signed his works as O.T. and is known for his Kopffussler (German: "Headfooters"), in which a body is formed by a head and very long legs and hands. He is not the first to draw these, but most likely the best known.
Tschirtner was raised by his aunt and uncle, and was very religious. He intended to become a priest, but as he realized it was not possible, he started to study chemistry. He did not finish his studies, however, as he was drafted into the German Army in 1937. In the war, he ended up as a POW in France. In 1946 he returned to Austria, but had to enter a psychological hospital in 1947.
In the hospital, dr. Leo Navratil encouraged him to draw: Tschirtner rarely initiated drawings of his own, but he made idiosyncratic versions of photographs or paintings. His personality was reserved and he would answer questions with a simple "yes" or "no". He would also obediently produce works when requested, but how near the end result would be to the request was not necessarily great.
In 1954 he was admitted to Haus der Künstler Gugging (House of Artists) where he lived the rest of his life. He died peacefully after a brief period in a hospital.
O.T. also provided inspiration for the 1983 Einstürzende Neubauten album Zeichnungen des Patienten O.T. (Drawings of Patient O.T.).