SM UB-26 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 30 April 1915 and launched on 14 December 1915. She was commissioned into the German Imperial Navy on 7 January 1916 as SM UB-26. UB-26 was trapped in anti-submarine nets trailed by the French destroyerTrombe and was scuttled in Le Havre harbour on 5 April 1916. She was raised by the French on 30 August 1917 and served as Roland Morillot until 21 January 1925. She was used in tests before finally being broken up in Cherbourg in 1935.