The Battle off Samar (Filipino: Labanan sa may Samar) was the centermost action of the Battle of Leyte Gulf, one of the largest naval battles in history, which took place in the Philippine Sea off Samar Island, in the Philippines on October 25, 1944. It was the only major action in the larger battle in which the Americans were largely unprepared. The Battle off Samar has been cited by historians as one of the greatest last stands in naval history; ultimately the Americans prevailed over a massive armada—the Japanese Imperial Navy's Center Force under command of Vice Admiral Takeo Kurita—despite their very heavy casualties and overwhelming odds.

Admiral William Halsey Jr. was lured into taking his powerful Third Fleet after a decoy fleet, taking with him every ship in the area that he had the power to command. The remaining American forces in the area were three escort carrier groups of the Seventh Fleet. The escort carriers and destroyer escorts which had been built to protect slow convoys from submarine attack had been adapted to attack ground targets and had few torpedoes, as they normally relied on Halsey's fleet to protect them from armored warships.

A Japanese surface force of battleships and cruisers—led by the super battleship Yamato, the largest and most heavily-gunned ship afloat—had been battered earlier in the larger battle and was thought to have been in retreat. Instead it had turned around unobserved and encountered the northernmost of the three groups, Task Unit 77.4.3 ("Taffy 3" ), commanded by Rear Admiral Clifton Sprague. Taffy 3's three destroyers and four destroyer escorts possessed neither the firepower nor the armor to oppose the 23 ships of the Japanese force capped by the Yamato's 46 cm (18-inch) guns but attacked anyway with 5-inch (127 mm)/38 caliber guns and torpedoes to cover the retreat of their slow "jeep" carriers. Aircraft from the carriers of Taffy 1, 2 and 3, including FM-2 Wildcats, F6F Hellcats and TBM Avengers, strafed, bombed, torpedoed, rocketed, depth-charged and made numerous "dry" runs at the Japanese force when they ran out of ammunition.[2]

The force lost two escort carriers, two destroyers, a destroyer escort and several aircraft. Over a thousand Americans died, comparable to the combined losses of American men and ships at the Coral Sea and Midway. The Americans sank three Japanese cruisers, disabled another three and caused enough confusion to persuade Admiral Kurita to regroup and ultimately withdraw, rather than advancing to sink troop and supply ships in Leyte Gulf. Half of all Americans killed at Leyte Gulf were killed in the battle. Although the battleship Yamato and the remaining force returned to Japan, the battles marked the final defeat of the Imperial Japanese Navy, as the ships remained in port for most of the rest of the war and ceased to be an effective naval force.[3]