The Battle of Vella Gulf (ベラ湾夜戦, Berawan yasen) was a naval battle of the Pacific campaign of World War II fought on the night of 6–7 August 1943 in Vella Gulf between Vella Lavella and Kolombangara in the Solomon Islands of the southwest Pacific.

This engagement was the first time that American destroyers were allowed to operate independently of the American cruiser force during the Pacific campaign.

In the battle, six American destroyers had intelligence that a Japanese group was coming to Vella Gulf on that night, and laid in wait for them. In the battle, six American destroyers engaged four Japanese destroyers attempting to reinforce Japanese troops on Kolombangara. The American warships closed the Japanese force undetected with the aid of radar and fired torpedoes, sinking three Japanese destroyers with no damage to American ships.

After their victory in the Battle of Kolombangara on 13 July 1943, the Japanese had established a powerful garrison of 12,400 around Vila on the southern tip of Kolombangara in an attempt to block further island hopping by the American forces, which had taken Guadalcanal the previous year as part of Operation Cartwheel. Vila was the principal port on Kolombangara, and it was supplied at night using fast destroyer transport runs the Americans called the "Tokyo Express". Three supply runs—on 19 July, 29 July, and 1 August—were completed.

During the final run on 1 August, a force of 15 U.S. PT boats launched an unsuccessful attack, firing between 26 and 30 torpedoes. Four Japanese destroyers responded, and in the ensuing battle PT-109, captained by Lieutenant John F. Kennedy, later President of the United States, was rammed and sunk by Amagiri. By 5 August, the Americans were driving towards the Japanese-held airfield at Munda on New Georgia just south of Kolombangara, and the Japanese decided to send a fourth transport run to Vila with reinforcements.

On the night of 6 August, the Imperial Japanese Navy sent a force of four destroyers under Captain Kaju Sugiura—2 Kagero-class: Hagikaze, Arashi and 2 Shiratsuyu-class: Kawakaze of Sugiara's own Destroyer Division 4 and Shigure of Captain Tameichi Hara's Destroyer Division 27—carrying about 950 soldiers and their supplies. The Japanese airfield at Munda, which the force at Vila was assigned to reinforce, was on the verge of being captured; it actually fell later that day. The Imperial Japanese commanders expected that Vila would become the center of their next line of defense. The Japanese operational plan specified the same approach route through Vella Gulf as the three previous successful transport runs over the objections of Hara, who argued that repeating prior operations was courting disaster.

The U.S. Navy Task Group 31.2 (TG 31.2) of six destroyers—USS Dunlap, Craven, Maury, Lang, Sterett, and Stack—commanded by Commander Frederick Moosbrugger, having been forewarned of the Japanese operation, was dispatched to intercept the Japanese force. The morale of Moosbrugger's crews was buoyed by the realization that at last they would be free of the combat doctrine that required them to stick close to the cruisers; on this night, they would be able to apply their own tactics.

The U.S. ships made radar contact with the Japanese force at 23:33 on 6 August. Moosbrugger's battle plan divided his forces into two divisions. Moosbrugger's own Destroyer Division 12 (Dunlap, Craven and Maury), whose ships retained their full pre-war torpedo batteries, was to launch a surprise torpedo attack out of the shadow of Kolombangara. Meanwhile, Commander Roger Simpson's Destroyer Division 15 (Lang, Sterett and Stack), whose ships had exchanged some of their torpedo tubes for extra 40 mm guns, was to cover Moosbrugger's division from an overwatch position, turning to cross the enemy's course. The idea was that any attempt by the Japanese to turn into the first division's torpedo attack would expose their broadsides to torpedo attack from the second division.