Karl Gustav Wilhelm Buck (17 November 1894, Stuttgart – 11 June 1977, Rudersberg) was a German SS-Hauptsturmführer and Lagerkommandant.
From 1933 until 1940 Buck was the commander of the concentration camp Heuberg, Oberer Kuhberg and Lager Welzheim, from 1940 of the Sicherungslager Schirmeck-Vorbruck [de] in Alsace.
He lost his left leg in a work accident in Chile, afterwards he returned to Germany.
He joined the Gestapo and changed from the SA to the SS where he was enlisted as number 490,187.
[1] In 1955 he was released and handed to German authorities that opened 7 accusations on him that were turned down as they had been judged by the Allies before.