Returning to Boston for brief overhaul 3 December 1943, "Forrest" spent the months of January and February 1944 training precommissioning crews for new destroyers, and escorting the aircraft carrier during her shakedown training off Bermuda. Between 7 March and 2 April, she patrolled the Atlantic with the hunter-killer group headed by the escort carrier . "Forrest" sailed from Norfolk 20 April for Northern Ireland, and took up escort duties around the British Isles as men and ships were concentrated for the Normandy invasion. When bad weather postponed the landings, originally intended for 5 June, "Forrest" was sent out on 4 June to recall convoys which had already sailed, bound for Utah Beach. During the actual invasion of 6 June, she screened transports lying in the Baie de la Seine, and on 12, 16, and 17 June, she bombarded shore targets to aid the troops advancing ashore. After escorting battleships to Plymouth, England, 18 June, "Forrest" returned to the assault area 21 June to cover sweeping operations off the Cotentin Peninsula. She engaged shore batteries on 22 and 24 June, returning to the Isle of Portland, England, the next day. Four days later "Forrest" got underway for Belfast, Oran, and Taranto, from which she sailed 11 August 1944 for the invasion of southern France, arriving in the inner fire support area off St. Tropez on 15 August. For the next two months, she escorted convoys from Palermo, Naples, Ajaccio, and Oran to the southern coast of France, guarding the men and supplies which made the push northward possible. She returned to Norfolk 8 November for conversion to a high speed minesweeper. "Forrest" trained in Chesapeake Bay for Pacific duty, for which she sailed 17 January 1945, calling at San Diego and Pearl Harbor for further training and arriving Ulithi on 9 March 1945. Ten days later she sortied for minesweeping operations to clear Okinawa waters for the assault on 1 April, after which she served in patrol, screened smaller minesweepers, performed local escort missions, and carried put the usual multiplicity of destroyer assignments. Several times she assisted ships stricken by "kamikaze" attacks, and on 27 May her own turn came. Three enemy aircraft were sighted, two of which she downed. The third, however, crashed her starboard side at the waterline, killing 5 and wounding 13 of her men. As damage control and fire fighting measures were being taken she headed for Kerama Retto and repairs.