The 'Action of Port Cros' was the US seizure of the island of Port Cros, off the southern coast of France, from the Germans within 'Dragoon' (i) (15 August 1944).

The action started as a US warship encountered two German warships while supporting 'Dragoon' (i), and this was one of the few surface engagements fought between the US Navy and the German navy. Later in that same day, Colonel Edwin A. Walker’s combined US and Canadian 1^st Special Service Force was dropped on the main island and captured the German-held positions.

The US destroyer Somers, armed with six 5-in (127-mm) guns and eight 21-in (533-mm) torpedo tubes, was cruising off the southern coast of France on 15 August when she came across the 738-ton former Italian 'Gabbiano' class corvette Camoscio that had been seized by the Germans in 'Achse' (ii) during September 1943 and recommissioned as UJ 6081. Also involved was the 917-ton former French aviso (patrol vessel) Amiral Senes recommissioned by the Germans as SG 21. UJ 6081 was armed with one 100-mm (3.93-in) gun and two 450-mm (17.7-in) torpedo tubes, and SG 21 with two 105-mm (4.13-in) guns. It was early morning off Port Cros, about four hours before the first 'Dragoon' (i) landings in Vichy France, when Somers spotted UJ 6801. Commander William C. Hughes ordered a torpedo attack.

A salvo of torpedoes was launched and the Germans opened fire as they attempted to manoeuvre out of the torpedoes' path. One torpedo struck UJ 6081's hull, however, and the corvette quickly began to sink. SG 21 was then spotted coming to the rescue of UJ 6801's survivors, and was engaged by the US destroyer’s main armament. The ensuing duel lasted for a few minutes until SG 21 was hit several times and began taking in water. Within a few more minutes, both German ships had sunk and Somers therefore left the area to prepare for her designed naval fire support missions against targets along the French mainland. The Americans suffered neither damage nor casualties.

Later on that same day, a mixed force of 1,800 US and Canadian infantrymen of the 1^st Special Service Force was dropped onto Port Cros and captured the five forts after a day-long battle with their German garrisons. The Allies assaulted two or three forts, and seized the others without resistance. Nine paratroopers were killed in the land battle.

After the engagement, US forces occupied Le Levant, Port Cross’s neighbour, and on 17 August, the corvette UJ 6082 (ex-Italian Antilope) and the former Egyptian armed yacht Nimet Allah were sunk by US destroyer Endicott with help from two British gunboats at the 'Action off La Ciotat'.