The Océan-class ships of the line were a series of 118-gun three-decker ships of the line of the French Navy, designed by engineer Jacques-Noël Sané. Fifteen were completed from 1788 on, with the last one entering service in 1854; a sixteenth was never completed, and four more were never laid down.

The first two of the series were Commerce de Marseille and États de Bourgogne in the late 1780s. Three ships to the same design followed during the 1790s (a further four ordered in 1793–94 were never built). A second group of eleven were ordered during the First Empire; sometimes described as the Austerlitz class after the first to be ordered, some of the later ships were not launched until after the end of the Napoleonic era, and one was not completed but broken up on the stocks. A 'reduced' (i.e. shortened) version of this design, called the Commerce de Paris class, with only 110 guns, was produced later, of which two examples were completed.

The 5,095-ton 118-gun type was the largest type of ship built up to then, besting the Spanish ship Santísima Trinidad. Up to 1790 Great Britain, the largest of the battle fleet nations, had not built especially large battleships because the need for large numbers of ships had influenced its battleship policy. The French initiated a new phase in battleship competition when they laid down a large number of three-deckers of over 5,000 tons.

Along with the 74-gun of the Téméraire type and the 80-gun of the Tonnant type, the Océan 120-gun type was to become one of the three French standard types of battleships during the war period 1793 to 1815.

These were the most powerful ships of the Napoleonic Wars and a total of ten served during that time. These ships, however, were quite expensive in terms of building materials, artillery and manpower and so were reserved for admirals as their fleet flagships.

Some of the ships spent 40 years on the stocks and were still in service in 1860, three of them having been equipped with auxiliary steam engines in the 1850s.