Rudolf Wacker was an Austrian painter.
Rudolf Wacker was born the fourth and youngest child of Romedius Wacker from Thaur in Tirol and Marianne (née Wüstner) from Mellau, Bregenzerwald in Bregenz.

Romedius Wacker was a successful master builder and lived with his family in a self-built villa with a large garden at Römerstrasse 24, which he built around 1900. During World War I, Wacker was drafted into the military. He was taken prisoner by the Russians in Poland in 1915 and spent five years in Tomsk, Siberia. After the so-called annexation of Austria in 1938, Wacker was targeted by the National Socialists, since he was said to have a close relationship with communism. Among other things, he took part in peace rallies and openly opposed the cultural policies of the National Socialists.

Wacker suffered two heart attacks during a house search and during an interrogation by the Gestapo and soon died at his parents' home in Bregenz.