SM UB-77 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 2 October 1917 as SM UB-77.
UB-77 was surrendered on 16 January 1919 in accordance with the requirements of the Armistice with Germany and broken up in Swansea in 1921.
See main article: Type UB III submarine. UB-77 was ordered by the GIN on 23 September 1916.
She was built by Blohm & Voss of Hamburg and following just under a year of construction, launched at Hamburg on 5 May 1917. UB-77 was commissioned later that same year under the command of Kptlt. Wilhelm Meyer. Like all Type UB III submarines, UB-77 carried 10 torpedoes and was armed with a 8.82NaN2 deck gun. UB-77 would carry a crew of up to 3 officer and 31 men and had a cruising range of 8680nmi. UB-77 had a displacement of 516lk=inNaNlk=in while surfaced and 648t when submerged. Her engines enabled her to travel at 13.6kn when surfaced and when submerged.
| Date | Name | Nationality | Tonnage[1] | Fate[2] | |
|---|---|---|---|---|---|
| 5 February 1918 |  United Kingdom | 14,348 | Sunk | ||
| 31 March 1918 | United Kingdom | 20,904 | Damaged | ||
| 28 August 1918 | Lompoc | United Kingdom | 7,270 | Damaged |