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 1 April 1916. She was commissioned into the German Imperial Navy on 19 July 1916 as SM UB-38. The submarine sank 47 ships in 21 patrols. UB-38 struck a mine and sank in the English Channel on 8 February 1918.