In 1943, the Axis powers plan an assault on the island of Kheros — where 2,000 British soldiers are marooned — to display their military strength and convince neutral Turkey to join them. Rescue by the Royal Navy is prevented by two massive radar-directed superguns on (fictional) nearby Navarone Island. When aerial bombing efforts fail, Allies of World War II Intelligence gathers a commando unit to infiltrate Navarone and destroy the guns. Led by Major Roy Franklin (Anthony Quayle), the team is composed of Captain Keith Mallory (Gregory Peck), a renowned spy; Colonel Andrea Stavrou (Anthony Quinn) from the defeated Greek army; Franklin's best friend Corporal Miller (David Niven), an explosives expert and former chemistry teacher; Greco-American Spyros Pappadimos (James Darren), a native of Navarone; and "Butcher" Brown (Stanley Baker), an engineer and expert knife fighter.
In 1943, Major Keith Mallory (Robert Shaw (British actor)) and Sergeant Donovan "Dusty" Miller (Edward Fox (actor)) are sent to find and "eliminate" Nicolai (a German spy, Colonel von Ingorslebon), who is believed to have successfully infiltrated the Yugoslav Partisans as "Captain Lescovar" (Franco Nero).