Karl Proisl (Traisen, 9 July 1911 - Beograd, 2 December 1949) was an Austrian sprint canoeist who competed in the 1930s.
At the 1936 Summer Olympics in Berlin, he won two medals with his partner Rupert Weinstabl: a silver in the C-2 1000 m event and a bronze in the C-2 10000 m event.
Proisl also won two medals at the 1938 ICF Canoe Sprint World Championships in Vaxholm: a gold in the C-2 1000 m event and silver in the C-2 10000 m event. He competed for Germany because it had annexed Austria at the time of the championships.