In May of 1942, the U.S. fleet pushed back a Japanese invasion force headed for New Guinea in the Battle of the Coral Sea, setting back Japan's ambitions to achieve clear naval and aviation superiority in the western Pacific. Despite the loss, Imperial Japanese Navy commander Admiral Isoroku Yamamoto was confident in his troops' superior numbers. Yamamoto, inspired by the success of the Pearl Harbor attack, planned a surprise attack on the Allied base at Midway Island to destroy the remaining U.S. Pacific fleet. The island of Midway sits in the Pacific Ocean, roughly halfway between the United States and Japan. Yamamoto planned a three-pronged attack on Midway after a smaller Japanese force attacked the Aleutian Islands off the coast of Alaska to distract the Allies. The Japanese aircraft carriers Akagi, Kaga, Hiryu, and Soryu, under the direction of Vice Admiral Chuichi Nagumo, launched an initial air attack on the island. Second, a fleet of ships and an army led by Vice Admiral Nobutake Kondo to invade the country. Finally, a combined attack by Nagumo's forces and Yamamoto's own navy, which would be waiting 600 miles to the west, once the predicted U.S. reinforcements from Pearl Harbor arrived.

By the beginning of 1942, U.S. Navy cryptanalysts had cracked Japanese communication codes and learned that Japan was planning an attack in the Pacific at a place they referred to as "AF." The Navy decided to send out a hoax message from the base, saying it was out of fresh water, because it was likely Midway. A similar message regarding "AF" was broadcast by Japanese radio operators shortly after, validating the intended target of the attack. Yamamoto was forced to communicate his strategy over the radio due to the dispersed nature of the Japanese fleet, and this gave Navy cryptanalysts in Hawaii enough information to determine the date of the attack (June 4 or 5) and the Imperial Japanese Navy's order of battle. Admiral Chester W. Nimitz, head of the United States Pacific Fleet, might use this intel to design a counterinvasion strategy. The Japanese believed the American aircraft carrier Yorktown would be out of commission at Midway because of damage sustained in the Battle of the Coral Sea. After only two days of repairs at the Pearl Harbor Navy Yard, the damaged carrier departed on May 30 to join the other U.S. ships near Midway in anticipation of the Japanese attack.

U.S. B-17 Flying Fortress bombers took off from Midway to attack Kondo's invasion force, thinking it was the main Japanese fleet after the Japanese diversionary attack on the Aleutian Islands on June 3. The first military action of the Battle of Midway was this unsuccessful assault. The next morning, more B-17s departed Midway for another fruitless attack on the Japanese invasion force. While this was going on, Nagumo dispatched 108 Japanese airplanes from the four aircraft carriers to attack Midway as part of the first phase of the Japanese attack. U.S. anti-aircraft defenses and the airport were still operational after the first Japanese attack, which caused significant damage to the facility but stopped by 7 a.m. Later, shortly after his pilots had warned Nagumo that another airstrike against the base was necessary, U.S. planes launched from Midway began targeting the four Japanese carriers, without result. A Japanese scout plane sighted the USS Yorktown and other ships of the American force to the east of Midway as Nagumo readied his planes for a second air attack. When the rest of the Japanese planes returned from Midway, Nagumo shifted strategies and ordered the armed planes to be ready to attack the American ships. As the Japanese ships were being attacked, a swarm of American Devastator torpedo bombers from the US carriers Hornet and Enterprise arrived. Almost all of them were destroyed by Japanese Zero fighters because they were not escorted by other planes. Another wave of U.S. carrier-launched bombers attacked an hour later, setting fire to the Japanese carriers Akagi, Kaga, and Soryu as their pilots refueled and rearmed their planes. The last remaining Japanese carrier, the Hiryu, promptly responded by launching two waves of strikes on the Yorktown, which was forced to abandon ship but managed to stay afloat. After destroying three Japanese carriers, the United States sent their dive bombers to destroy the fourth, the Hiryu.

Major fighting at the Battle of Midway ended on the evening of June 4, but for the next two days, American forces at sea and on Midway Island continued to attack the Japanese. Cover was given by the destroyer USS Hammann for the damaged carrier Yorktown during recovery operations; however, on June 6, a Japanese submarine arrived and fired four torpedoes, damaging both American vessels. The Hammann went down in a matter of minutes, while the Yorktown took all of the next day to capsize and sink. The Battle of Midway was finally over when Yamamoto ordered his ships to retreat on June 6. In total, the conflict cost both sides heavily; Japan lost an estimated 3,000 personnel (including almost 200 of their best experienced pilots), about 300 aircraft, one heavy cruiser, and four aircraft carriers; the United States lost the Yorktown and the Hammann and roughly 360 servicemen. Since the United States won the Battle of Midway, Japan has been on the defensive throughout the Pacific Theater of World War II instead of trying to expand its influence. The battle bolstered American morale and depleted Japanese will to fight, drastically altering the course of the Pacific War in favor of the Allies.