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 November 1942.

Le Centaure was part of a fairly homogeneous series of 31 deep-sea patrol submarines also called "1,500-tonners" because of their displacement.

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).

When submerged, their two electric motors produced a combined 2,250 horsepower (1,678 kW) and allowed them to reach 10 knots (19 km/h; 12 mph).

Also called "deep-cruising submarines", their range on the surface was 10,000 nautical miles (19,000 km; 12,000 mi) at 10 knots (19 km/h; 12 mph).

[5][7] In response to a request by the British, Le Centaure and Argo got underway from Casablanca on 19 September 1939 to assist the British – who had only two submarines available for the task – in reconnoitering the Azores and the Canary Islands, where the Allies suspected German merchant ships had taken refuge upon the outbreak of war and were serving as supply ships for German U-boats.

She proceeded from Bizerte to Toulon, where at the end of June 1940 she was disarmed, defueled, and placed under guard in acordance with the terms of the armistice.

[5] On 12 November 1941, Le Centaure and her sister ship Bévéziers were designated to relieve Monge and Pégase on overseas stations.

[16] At Philadelphia, Le Centaure′s Schneider diesel engines underwent a full overhaul,[5] her batteries were replaced, her hull was thickened and her diving planes reinforced to increase her test depth, and some of her ballast tanks were transformed into fuel tanks to increase her range.

A significant effort went into improving her soundproofing,[14] and radars, more efficient listening gear, a sonar, a new pitometer log, a new bathythermograph,[5][17] air conditioning, and a refrigerator were installed aboard her.

[5] According to one source, she was back in Bermuda in February 1945,[2] but by March 1945 she was at Oran[2][5] in French Algeria, where she spent the rest of World War II in training with Archiméde, Casabianca, Le Glorieux, and destroyers in preparation for a transfer to the Pacific Ocean to participate in the war with Japan.