Sailing from France on his second cruise, Hailey made a rapid circuit of Ireland and Scotland, landing several times and holding small coastal towns for ransom.

She sortied from Pearl Harbor 19 January 1944 screening a unit of Admiral Richmond Kelly Turner's Southern Attack Force for the assault and occupation of the Marshall Islands.

She sailed from Kwajalein 15 February with the Eniwetok Expeditionary Group and arrived off Eniwetok next day to screen the heavy ships; then joined Admiral Jesse Oldendorf's Northern Support Group in battering strong enemy emplacements before retiring to Majuro Atoll screening Manila Hay.

The destroyers continued their search until the following evening without regaining contact—but they recovered souvenirs of Japanese origin from a diesel oil slick that extended over 7 miles (11 km) of ocean.

The remainder of August and September Hailey screened a group of escort carriers furnishing air support for the seizure and occupation of Peleliu, Ngesebu, and Anguar Islands in the Palaus.

Hailey next sortied from Seeadler Harbor, Manus Island, 12 October with Admiral Felix Stump's "Taffy 2" (Task Unit 77.4.2) the center formation of the three escort carrier groups off the entrance to Leyte Gulf.

The experienced destroyer next joined the Fast Carrier Task Force (then TF 38 of Admiral William F. Halsey's 3rd Fleet), as a unit of Rear Admiral Gerald F. Bogan's Task Group 38.4 (TG 38.4) launching strikes on Formosa, before joining Captain Acuff's fueling group for the 3d Fleet.

In February 1945 Hailey joined Admiral Marc A. Mitscher's Fast Carrier Task Force 58 and until the last of June participated in bombardments and strikes, inflicting much damage to the enemy on Okinawa and the Japanese home islands where "the fleet had come to stay."

Joining Fast Carrier Task Force 77 (TF 77), she took part in blockading operations and provided close fire support for ground troops in Korea.