Salvatore Castagna (Caltagirone, 14 January 1897 – Rome, 3 February 1977) was an officer in the Royal Italian Army during World War II, most notable for his leadership during the siege of Giarabub.

In 1937, with the rank of major, he returned there as commander of the garrison of Yefren, then of Bardia and finally of Giarabub (Jaghbub), an oasis in the Western Desert surrounded by dunes, 50 kilometers from the Egyptian border and 300 from the sea, where he still was at the start of the Second World War.

[1] Giarabub was the last Italian stronghold in Cyrenaica during Operation Compass, the first British offensive in North Africa in which the Tenth Army was routed and annihilated.

Cut off by the Allied advance in December 1940, Castagna and his garrison of 750 Libyans (most of whom deserted during the siege) and 1,350 Italians held out for three months before being overwhelmed by the final Australian assault on 21 March 1941.

Castagna, who had been promoted to colonel during the siege, was wounded in the head during the final assault, captured and taken to a British hospital in Palestine and then, after recovery, to a prisoner-of-war camp in India, near Bombay, where he remained until well after the end of the war.