Siegfried Wolfgang Fehmer (10 January 1911 in München – 16 March 1948) was a German Gestapo officer during World War II. He was stationed in Norway during the occupation of Norway by Nazi Germany, and at the end of the war he was a Kriminalrat, the police investigator heading the infamous Abteilung IV from its headquarters in Victoria Terrasse, Oslo. He had also reached the rank of Hauptsturmführer in the SS. Along with Josef Terboven, Fehmer was considered one of the most despised members of the German occupation forces in Norway.
Fehmer joined the National Socialist German Workers Party in January 1930 and was employed by the Gestapo from 1934. He was promoted several times and held different positions within the organization, until in April 1940 he was sent to Norway. There he worked with counter-intelligence and suppressing the resistance.
Fehmer wore an SS uniform with Sicherheitsdienst badges. The Sicherheitsdienst (SD, Security Service) was primarily the intelligence service of the SS and the Nazi Party in Nazi Germany. With a striking appearance and charm, he was perceived as quite the ladies man. Despite this outward appearance, Fehmer was ruthless, and did not hesitate to use torture during interrogation of suspects. He has been described by his victims as capable of switching from using a friendly approach to sadistic torture in a heartbeat.
Milorg (the military branch of the Norwegian resistance movement) saw him as a severe threat. Several plans for his assassination were made, and Fehmer survived one such attack with several gunshot wounds to his chest.