Which American commander said "We have met the enemy and they are ours"?

The American commander who said “We have met the enemy and they are ours” was Oliver Hazard Perry.

Perry made the statement in his report after commanding the American squadron at the Battle of Lake Erie on September 10, 1813. The battle was a decisive American naval victory over a British squadron led by Robert Heriot Barclay. Perry first fought from his flagship, USS Lawrence, whose crew suffered heavily under British fire.

When Lawrence became badly damaged, Perry transferred to USS Niagara and continued the attack. The American fleet broke the British line and captured the opposing ships. Perry then sent his famous message to General William Henry Harrison, reporting the victory and listing the captured vessels.

The quotation is often shortened to “We have met the enemy, and they are ours,” but it originally appeared in a fuller battle report. Perry is also associated with the slogan “Don’t Give Up the Ship,” a tribute to Captain James Lawrence. The Lake Erie victory helped secure American control of the lake and enabled Harrison's later campaign in the western theater.