Indus was laid down 4 October 1943 as liberty ship SS Theodore Roosevelt (MCE hull 1814) by Bethlehem-Fairfield Shipyard, Baltimore, Maryland, under a Maritime Commission contract; launched 29 October 1943; sponsored by Mrs. William MacMillan, granddaughter of President Theodore Roosevelt; acquired by the Navy 5 November 1943; converted at the Maryland Drydock Company; and renamed Indus.

Indus then returned to Milne Bay 27 September, and soon afterward became flagship for Commander 7th Fleet Service Forces during the Leyte operation.

The versatile ship issued stores and did repair work during this period, and during the numerous air raids shot down at least two Japanese aircraft.

As the next major assault in the Philippines, the Lingayen Gulf operation, began to take shape at staging bases, Indus joined the service group and departed 28 December for the landing.

Although the Japanese made desperate air attacks on the convoy, sinking some ships but suffering heavy losses themselves, the fleet resolutely drove through to its objective.