SM UC-25 was a German Type UC II minelaying submarine or U-boat in the German Imperial Navy (German: Kaiserliche Marine) during World War I. The U-boat was ordered on 29 August 1915 and was launched on 10 June 1916. She was commissioned into the German Imperial Navy on 28 June 1916 as SM UC-25. In 13 patrols UC-25 was credited with sinking 21 ships, either by torpedo or by mines laid. From March to September 1918, she was commanded by Karl Dönitz, later grand admiral in charge of all U-boats in World War II. UC-25 was scuttled at Pola on 28 October 1918 on the surrender of Austria-Hungary.