Operating from San Diego as flagship of Destroyer Squadron 5 (see table), she and her squadron participated in training exercises and large-scale fleet problems until the outbreak of World War II.
On 5 December 1941, Porter with DesDiv 9 of her squadron (Drayton, Flusser, Lamson and Mahan) departed Pearl Harbor with Lexington’s Task Force 12 (also including heavy cruisers Chicago, Portland and Astoria) to deliver Marine scout bombers to Midway Island and were at sea when the Japanese attacked on 7 December, returning to Pearl Harbor 13 December after searching to “intercept and destroy” the enemy.
Porter remained in Hawaiian waters until March 1942, when she began four months’ operations off the west coast. Returning to Pearl Harbor in August, she sortied on 16 October for the Solomons with Enterprise’s Task Force 16—battleship South Dakota, heavy cruiser Portland, anti-aircraft cruiser San Juan and destroyers Mahan, Conyngham, Shaw, Cushing, Smith, Preston and Maury. Ten days later, following the Battle of the Santa Cruz Islands, Porter was hit by the torpedo carried by the Avenger torpedo plane whose crew she stopped to rescue. After the crew had abandoned ship, was sunk by gunfire from Shaw.
Porter earned one battle star in World War II for this action.