Karl Eugen Julius Wirtz (24 April 1910 – 12 February 1994) was a German nuclear physicist, born in Cologne.
He was arrested by the allied British and American Armed Forces and incarcerated at Farm Hall for six months in 1945 under Operation Epsilon.
In 1938, he completed his Habilitation at the Humboldt University of Berlin with a Habilitationsschrift on the electrochemical foundations of electrolytic heavy water production.
In 1944, Wirtz was appointed head of the experimental department at the KWIP, which had been moved to Hechingen in 1943 to avoid bombing casualties to the personnel.
In late spring 1945, Wirtz was arrested by the allied British and American Armed Forces and incarcerated at Farm Hall for six months under Operation Epsilon.