The Glorious First of June (also known as the Third Battle of Ushant and in French as the Bataille du 13 prairial An 2) was a naval battle fought in the Atlantic Ocean on June 1, 1794 between the Royal Navy and the navy of Revolutionary France. It was the first major naval battle of the French Revolutionary Wars.

On 11 April 1794, with France suffering from food shortages, a convoy of 117 merchant ships sailed from the United States bringing grain. On 19 May the French squadron based at Brest and commanded by Rear Admiral Villaret-Joyeuse set to sea out to escort the convoy. The British blockading squadron under Admiral Richard Howe gave chase. Both sides had 26 ships of the line, the largest being the French Montagne of 120 guns. On 28 May, four hundred miles west of Ushant, the two fleets met, but it was late in the day and there was no engagement.

On 29 May, Howe attempted to pass through the French line of battle to get the weather gage, but managed to engage only the last 5 ships in the French line. For the next two days, the British gave chase, but visibility was poor and there was no engagement.

Finally, on 1 June 1794 (13 prairial An 2 in the French Revolutionary calendar), the British caught up with the French, this time possessing the critical weather gage. Howe descended on the French line, breaking through it in several places and engaging from leeward. The battle rapidly turned into a general mélée which lasted all day. The French ships Sans-Pareil, Juste, America, Impetueux, Northumberland, and Achille were captured, and the Vengeur du Peuple sank after a four-hour duel with HMS Brunswick.

After hours of pounding, the French withdrew again, returning to Brest this time, but the British were in no condition to pursue: Defence and Marlborough had to be towed back to port.

The French had lost 7 ships, with a further 13 severely damaged, and had suffered perhaps 1,500 killed, 2,000 wounded and 3,000 captured, while the British had 8 seriously damaged ships, 287 killed and 811 wounded.

Both sides could claim a tactical victory: the British in the battle itself, but the French achieved the object of their campaign, since the grain convoy reached Brest safely.

Strategically the battle was a victory for the British: the French navy never again tried to fight a convoy through the British blockade, resorting to blockade-running, privateering and trade through neutral countries.