Siegfried Wolfgang Fehmer (10 January 1911 in Munich – 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.