She participated in World War II, first on the side of the Allies from 1939 to June 1940, then in the navy of Vichy France until she was scuttled at Toulon in November 1942.

Propelled on the surface by two diesel engines producing a combined 6,000 horsepower (4,474 kW), they had a maximum speed of 18.6 knots (34.4 km/h; 21.4 mph).

[2] Orders called for Fresnel and her sister ships Achéron, Agosta, and Bévéziers to conduct such a cruise to Argentina.

[2] In December 1939, Fresnel joined Achéron, Agosta, Bévéziers and their sister ships Le Héros and Redoutable in forming a patrol line to search the central Atlantic Ocean for the German supply ship Altmark, but Fresnel was low on fuel and soon had to proceed to Casablanca in French Morocco to refuel.

[2] As of 6 February 1940, she and the other submarines of her division were based at Casablanca and still assigned to patrol in the Canary Islands, but Fresnel later was transferred to Bizerte in Tunisia.

[2][6] On 24 June 1940, she was sent along with her sister ships Le Tonnant and Pascal to patrol in the Mediterranean Sea south of Sardinia.

[2] Soon after arriving at Casablanca, Fresnel and Actéon got back underway on 22 April 1941 for a training cruise along the coast of French Morocco.

[2] In November 1942, the submarines of the 5th Submarine Division received orders to proceed to Toulon to undergo a major overhaul, but Fresnel and Actéon were still in French North Africa at Oran in Algeria when Allied forces landed on the coast of North Africa in Operation Torch on 8 November 1942.

[2] Jamaica sighted and evaded her torpedoes, and Fresnel subsequently survived three days of gunfire and depth-charging by counterttacking British warships, which pursued her all the way to the limits of Spanish territorial waters.

[3][10] The Germans seized Fresnel and handed her over to the Italians, who refloated her on either 28 or 29[3] January 1943, according to different sources, planning to refit her.