Arnulf Rainer (1929, Baden bei Wein) is the founder of Art Informel in Austria.

Mostly self-taught (he quit both the Vienna Academy of Applied Arts and Academy of Fine Arts in Vienna on the first day of classes due to creative differences), his early influences came from Surrealism. With Ernst Fuchs, Arik Brauer, and Josef Mikl, he founded the Hundsgruppe in 1950. Rainer broke with Surrealism, and came to his abstract forms and Art Informel, which he termed "microstructures "and "atomisations ".

Since the mid-1950s, his works are marked by overpainting, often with the colour black, and masking of illustrations. He would use photographs or illustrations, paintings by other artists, on which he built up an impasto. He painted blindfolded (automatism) or with his fingers and feet. His connection with the Vienna Actionists (which he was not a member of) comes from his use of drugs during painting and body art in the mid-1960s. Rainer used photography to make self-portraits in extreme states of emotion (Face Farces), which he then painted or overpainted. The expressions in the photographs were not as strongly reflected as Rainer wanted. To achieve better accentuation, he corrected the photos of certain accents that are important to him. From 1982, Arnulf Rainer has created the series featuring Hiroshima nuclear bombing and its consequences in all areas. Since the late 1970s, Rainer confronted the issue of death, using the cross motif in his works, and later creating death masks of notable individuals.

From 1981 to 1995, Rainer held a professorship at the Academy of Fine Arts in Vienna. In 1959, with Fuchs and Friedensreich Hundertwasser, Rainer founded the Pintorarium, an academy for all creative fields which was active until 1969. In 2009, the Arnulf Rainer Museum opened in Frauenbad in Baden.