Karl Dillinger was a German painter and art teacher. His works were classified as "degenerate" during the National Socialist era and were partially destroyed.

Dillinger was the son of master brewer Carl Dillinger. He studied at the Kunstgewerbeschule in Karlsruhe from 1899 to 1902 and at the Kunstakademie Stuttgart from 1902 to 1906. He then took part in courses at the Académie Julian and was a pupil of Adolf Hölzel and Robert von Haug. Before moving to the Badische Landeskunstschule Karlsruhe as a teacher in 1924, he worked as a freelance painter in Mannheim. In 1926 he received a professorship, which was revoked in 1933 for political reasons by the National Socialist rulers. He subsequently lived as a freelance artist in the Palatinate; he worked in Grethen and died in Dirmstein in 1941.

In 1937, his panel painting Landscape with Trees from the Staatliche Kunsthalle Karlsruhe and the panel painting Girl with Red Hair and the watercolor Orchard from the Städtische Kunsthalle Mannheim were confiscated and destroyed in the Nazi "Degenerate Art" campaign.