The Glauco-class was a class of two submarines built by CRDA in Trieste for the Royal Italian Navy (). The submarines had initially been ordered by the Portuguese government in 1931, but were finished for the Regia Marina when Portugal cancelled the order. Both boats were launched and commissioned in 1935, and both boats saw action in the Spanish Civil War and the Second World War. The Glauco was badly damaged by the British destroyer Wishart and scuttled by own crew as inoperable on the 27 June 1941, west of Gibraltar; Otaria was surrendered to the Allies in 1943 and used as a target by the Royal Navy in Malta until it was sent to the Junkyard in 1948.