 Bellerophon was in the West Indies when the Napoleonic Wars broke out in May 1803. Her captain, John Loring, was appointed commodore of the British squadron, which quickly went on the offensive against French shipping in the Blockade of Saint-Domingue. In mid-1803, the squadron under Captain Henry William Bayntun, consisting of HMS Bellerophon, Cumberland, Hercule, Elephant, and Vanguard captured the French privateers Poisson Volant and Superieure. The Royal Navy took both into service. The corvette Mignonne and a brig were captured in late June, after which the British patrolled off Cap-François. On 24 July the squadron, made up of Bellerophon and the 74-gun ships HMS Elephant, HMS Theseus and HMS Vanguard, came across two French 74-gun ships, Duquesne and Duguay-Trouin, and the frigate Guerrière, attempting to escape from Cap-François. The squadron gave chase, and on 25 July overhauled and captured Duquesne after a few shots were fired, while Duguay-Trouin and Guerrière managed to evade their pursuers and escape to France. One man was killed aboard Bellerophon during the pursuit. She remained blockading Cap-François until November, when the French commander of the garrison there, General Rochambeau, approached Loring and requested to be allowed to evacuate his men, which were being besieged by a native Haitian force led by Jean-Jacques Dessalines. To prevent Rochambeau escaping, Loring sent launches from Bellerophon and Elephant into the Caracol Passage where they cut out the French schooner Découverte on 22 – 23 November. The French formally surrendered on 30 November and were allowed to evacuate on three frigates, Surveillante, Clorinde, and Vertu, and a number of smaller ships, and were escorted to Jamaica by the squadron.
