The Einsatzgruppen Operational Situation Reports (OSRs), or ERM for the German: Die Ereignismeldung UdSSR, were dispatches of the Nazi death squads (Einsatzgruppen), which documented the progress of the Holocaust behind the German–Soviet frontier in the course of Operation Barbarossa, during World War II. The extant reports were sent between June 1941 and April 1942 to the Chief of the Security Police and the SD in Berlin, from the occupied eastern territories including modern-day Poland, Belarus, Ukraine, Russia, Moldova, and the Baltic Countries. During the Nuremberg War Crimes Trials the originals were grouped according to year and month and catalogued using a consecutive numbering system, as listed in the below table. The original photostats are held at the National Archives in Washington D.C.

Einsatzgruppen were Schutzstaffel (SS) paramilitary death squads of Nazi Germany that were responsible for mass murder, primarily by shooting, during World War II (1939–1945) in German-occupied Europe. The Einsatzgruppen had an integral role in the implementation of the so-called "Final Solution to the Jewish question" in territories conquered by Nazi Germany, and were involved in the murder of much of the intelligentsia and cultural elite of Poland, including members of the Catholic priesthood. Almost all of the people they murdered were civilians, beginning with the intelligentsia and swiftly progressing to Soviet political commissars, Jews, and Romani people, as well as actual or alleged partisans throughout Eastern Europe.