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 8.8 cm (3.46 in) deck gun. UB-77 would carry a crew of up to 3 officer and 31 men and had a cruising range of 8,680 nautical miles (16,080 km; 9,990 mi). UB-77 had a displacement of 516 t (508 long tons) while surfaced and 648 t (638 long tons) when submerged. Her engines enabled her to travel at 13.6 knots (25.2 km/h; 15.7 mph) when surfaced and 7.8 knots (14.4 km/h; 9.0 mph) when submerged.
^Helgason, Guðmundur. "WWI U-boat commanders: Wilhelm Meyer". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 4 February 2015.
^Helgason, Guðmundur. "WWI U-boat commanders: Franz Maurer". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 4 February 2015.
^Helgason, Guðmundur. "Ships hit by UB 77". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 4 February 2015.