Otto Kähler (3 March 1894 – 2 November 1967) was a German admiral during World War II. He commanded the German auxiliary cruiser Thor, a merchant raider, on two combat patrols and sank or captured 12 ships, for a combined tonnage of 96,547 gross register tons (GRT) of Allied shipping. He was a recipient of the Knight's Cross of the Iron Cross with Oak Leaves. Kähler relinquished command of Thor on 20 July 1941 to Günther Gumprich.