Oskar Ritter (born 1913, date of death unknown) was a German physicist.
During World War II, he worked on the German nuclear energy project, also known as the Uranium Club.
In the latter years of World War II, Berlin scientific organizations moved equipment and personnel out of the city to escape effects of Allied air raids.
The reports were classified Top Secret, they had very limited distribution, and the authors were not allowed to keep copies.
The reports were confiscated under the Allied Operation Alsos and sent to the United States Atomic Energy Commission for evaluation.