An officer until 1919, Ritter then became a designer and painter, first entering films in 1925 as a public relations man for Siidfilm and Emelka. In 1932 he was appointed Director and Production Manager for the UFA film company, a post he held until 1945.
Ritter was a convinced Nazi who managed to introduce a certain realism and artistry into films that were primarily political and propagandist in orientation. A master of action sequences in the best Hollywood style, Ritter glorified Prussian militarist traditions, the ‘heroism’ of the Wehrmacht, the spirit of camaraderie and above all the virile bravery of the fighter-pilots of the Luftwaffe - to which he devoted eight films after 1936.
Awarded the title of ‘Professor’ by Goebbels, Ritter combined reportage and fiction in his cinematic art, which faithfully reflected Nazi anti-communism in movies like GPU (1942) and the militarist ethos of official ideology.
After the war Ritter emigrated along with many former Nazis to Argentina, where he was head of Eos-Film Mendoza. He returned to Germany in 1954, where he continued to direct films, forming his own company Karl Ritter-Filmproduktion GmbH.
He died on 7 April 1977 in Buenos Aires.