SM U-80 was one of the 329 submarines serving in the Imperial German Navy in World War I.U-80 was engaged in the naval warfare and took part in the First Battle of the Atlantic.U-80 is credited for sinking the Laurentic, the 24th largest ship sunk in World War I by uboats, at 14,892 GRT. She struck two mines laid by U-80 off Malin Head, and sank within one hour. She went down with 345 casualties, and 35 tons of gold ingots.