SMS S20 was a V1-class torpedo boat of the Imperial German Navy. The ship was built by Schichau-Werke, at their Elbing shipyard, completing in 1913. S20 served with the German High Seas Fleet during the First World War, taking part in the Battle of Jutland in 1916 and moved to Flanders later in 1916. The ship was sunk by cruisers and destroyers of the British Harwich Force on 5 June 1917.