The Tonnant class was a series of eight 80-gun ships of the line designed in 1787 by Jacques-Noël Sané, whose plans for the prototype were approved on 29 September 1787. With sixteen gunports on the lower deck on each side these were the most effective two-deckers of their era. Their broadside of 1,102 livres equated to 1,190 British pounds weight, over 50% more than the standard British 74-gun ship, and even greater than that of a British 100-gun three-decker.

Jacques-Noël Sané was a French naval engineer. He was the creator of standardised designs for ships of the line and frigates fielded by the French Navy in the 1780s, which served during the French Revolutionary Wars and the Napoleonic Wars and in some cases remained in service into the 1860s. Captured ships of his design were commissioned in the Royal Navy and even copied.