Gerhard Köppen (17 May 1918 – 5 May 1942) was a German Luftwaffe ace and recipient of the Knight's Cross of the Iron Cross with Oak Leaves during World War II. The Knight's Cross of the Iron Cross and its higher grade Oak Leaves was awarded to recognise extreme battlefield bravery or successful military leadership. Gerhard Köppen is credited with 85 victories in 380 sorties and was posted missing in action on 5 May 1942.
Gerhard Köppen joined the military service in 1936. His initial posting was with Kampfgeschwader 1 "Hindenburg" (KG 1) before he was selected for fighter pilot conversion training in 1939. He was transferred to the 7th Staffel of Jagdgeschwader 52 (JG 52) in 1941. He was awarded the Knight's Cross of the Iron Cross (Ritterkreuz des Eisernen Kreuzes) after 40 aerial victories. He claimed four aircraft shot down on 24 February 1942 and was decorated with Knight's Cross of the Iron Cross with Oak Leaves (Ritterkreuz des Eisernen Kreuzes mit Eichenlaub) after 72 aerial victories on 27 February 1942.
He was promoted to Leutnant on 1 April 1942. He was posted as missing in action following combat flying a Bf 109 F-4 "white 4" (Werknummer 7303—factory number) north of Akmonaj. Köppen was last seen swimming in the Sea of Azov on 5 May 1942. His brother Eckardt Köppen was killed in action between Hochfließ and Grünweiden southeast of Gumbinnen on 15 January 1945 as Unteroffizier and company troop leader of the 1./Fallschirm-Panzer-Pionier-Bataillon 2 "Hermann Göring". He posthumously received the Knight's Cross of the Iron Cross on 15 March 1945.
- Ehrenpokal der Luftwaffe (17 November 1941)
- Front Flying Clasp of the Luftwaffe
- Iron Cross (1939) 2nd Class and 1st Class
- German Cross in Gold on 15 December 1941 as Feldwebel in the 8./JG 52
- Knight's Cross of the Iron Cross with Oak Leaves, Knight's Cross on 18 December 1941 as Feldwebel and pilot in the 7./Jagdgeschwader 52, 79th Oak Leaves on 27 February 1942 as Feldwebel and pilot in the 8./Jagdgeschwader 52
- Mentioned 4 times in the Wehrmachtbericht (25 February 1942, 3 May 1942, 6 May 1942 and 9 May 1942)