The Battle of the Strait of Otranto of 1917 was the result of an Austro-Hungarian raid during the Adriatic Campaign of World War I on the Otranto Barrage, an Allied naval blockade of the Strait of Otranto. The battle took place on 15 May 1917, and was the largest surface action in the Adriatic Sea during World War I. The Otranto Barrage was a fixed barrier, composed of lightly armed naval drifters with anti-submarine nets coupled with minefields and supported by Allied naval patrols.

The Adriatic Campaign of World War I was a naval campaign fought between the Central Powers and the Mediterranean squadrons of Great Britain, France, the Kingdom of Italy, Australia, and the United States.