SM UB-113 was a German Type UB III submarine or U-boat in the German Imperial Navy (German: Kaiserliche Marine) during World War I. She was commissioned into the German Imperial Navy on 25 April 1918 as SM UB-113. UB-113 was lost in autumn 1918 for unknown reasons. According to recent sources, SM UB-113 probably crossed paths with the French gunboat l'Engageante on 29 August in the Gulf of Gascony and was sunk. Occasional confusion with the SM UB-123, which also met a mysterious fate, remains.