The Richelieu class were fast battleships built for the French Navy between the 1930s and 1950s. Initially two ships were ordered in 1935 in response to Italian orders for the Littorio-class battleships the previous year. The Richelieus were based on the preceding Dunkerque class, but scaled up to accommodate more powerful 380 mm (15 in) guns and armor to protect them from guns of the same caliber. To keep the ships within the displacement limits imposed by the Washington Naval Treaty, they featured the same concentrated arrangement as the Dunkerques for the main battery: two quadruple gun turrets placed forward. They also incorporated new, more compact boilers that allowed for a shorter hull for the desired top speed. After Germany ordered two Bismarck-class battleships, France responded with another pair of Richelieus, to be built to modified designs. The first, Clemenceau, would have received modified secondary and anti-aircraft batteries, while Gascogne would have had had her superfiring main battery turret shifted aft, along with other changes. Clemenceau was never completed, and Gascogne was never laid down. The Richelieus were the last battleships built for the French Navy.

A fast battleship was a battleship which in concept emphasised speed without undue compromise of either armor or armament. Most of the early World War I-era dreadnought battleships were typically built with low design speeds, so the term "fast battleship" is applied to a design which is considerably faster. The extra speed of a fast battleship was normally required to allow the vessel to carry out additional roles besides taking part in the line of battle, such as escorting aircraft carriers.