SM UB-38 was a German Type UB II submarine or U-boat in the German Imperial Navy () during World War I. The U-boat was ordered on 22 July 1915 and launched on 28 December 1915. She was commissioned into the German Imperial Navy on 29 April 1916 as SM UB-38. The submarine sank 93 ships in 14 patrols. UB-38 struck a mine and sank in the English Channel on 17 May 1917.