"Courbet" became flagship of Vice-Amiral Charlier between 6 June 1919 and 20 October 1920. The following year she became a gunnery training ship at Toulon, but she suffered a serious boiler fire in June 1923 that caused her to be repaired and given the first of her upgrades between July and April 1924 at La Seyne-sur-Mer. She had another boiler fire in August 1924 and remained under repair for the rest of the year, but resumed her duties as a gunnery training ship upon her return from the dockyard. She was refitted again between January 1927 and January 1931. She was transferred from the gunnery school to the navigation school in 1937, before her final prewar refit between April 1937 to September 1938. By 1939 she reverted to her role as a gunnery training ship, but she was ordered to Brest and Quiberon with her sister "Paris" upon the outbreak of World War II.