SM U-106 was one of the 329 submarines serving in the Imperial German Navy in World War I. U-106 was commissioned on 28 Jul 1917, under the command of Kapitänleutnant Hans Hufnagel, and participated in one wartime patrol starting on 2 September 1917. On 18 September 1917, during the First Battle of the Atlantic, U-106 was credited with the sinking of HMS Contest, an Acasta class destroyer, and damaging "City of Lincoln", a 5,867 ton steamer, in the Western Approaches. She was lost off Terschelling after striking a mine on 7 October 1917.