The French expedition to Ireland, known in French as the Expédition d'Irlande (French pronunciation: [ɛkspedisjɔ̃ diʁlɑ̃d], "Expedition to Ireland"), was an unsuccessful attempt by the French Republic to assist the outlawed Society of United Irishmen, a popular rebel Irish republican group, in their planned rebellion against British rule during the French Revolutionary Wars. The French intended to land a large expeditionary force in Ireland during the winter of 1796–1797 which would join with the United Irishmen and drive the British out of Ireland. The French anticipated that this would be a major blow to British morale, prestige and military effectiveness, and was also intended to possibly be the first stage of an eventual invasion of Great Britain itself. To this end, the Directory gathered a force of approximately 15,000 soldiers at Brest under General Lazare Hoche during late 1796, in readiness for a major landing at Bantry Bay in December.
The operation was launched during one of the stormiest winters of the 18th century, with the French fleet unprepared for such severe conditions. Patrolling British frigates observed the departure of the fleet and notified the British Channel Fleet, most of which was sheltering at Spithead for the winter. The French fleet was subject to confused orders as it left port and was scattered across the approaches to Brest: one ship was wrecked with heavy loss of life and the others widely dispersed. Separated, most of the French fleet managed to reach Bantry Bay late in December, but its commanders were driven miles off course and without them the fleet was unsure of what action to take, with amphibious landings impossible due to the weather conditions, which were the worst recorded since 1708. Within a week the fleet had broken up, small squadrons and individual ships making their way back to Brest through storms, fog and British patrols.