The second U.S. Navy ship named Herndon (DD-638) was launched on 2 February and commissioned on 20 December 1942. The Herndon began war duties escorting a convoy from New York to Casablanca early in 1943. The Herndon also took part in the Sicilian Campaign, and during July 1943 she operated in the antisubmarine and fire-support missions, assisting troops in Southern Europe.
After departing the Mediterranean area of operations in August 1943, the Herndon again escorted troops and material, this time from the United States to Britain in preparation for the invasions at Normandy. Providing gunfire support during the 6 June 1944 D-Day operations, the Herndon operated ahead of the first assault waves, assisting with the indispensable bombardment of enemy positions around Omaha Beach. The Herndon was a part of the joint task force screening carriers when the invasion of Southern France began in August 1944.