After being commissioned, Steamer Bay conducted trials and went on a shakedown cruise down the West Coast, before arriving at San Diego.
On 14 May, she sailed for the New Hebrides, transporting Marine Air Group (MAG) 61.
She arrived at Espiritu Santo on 30 May, where her cargo was unloaded.
She departed on 2 June, arriving at San Diego on 20 June.
On 19 July, she loaded 298 marines and 72 aircraft, and proceeded westwards for the Marshall Islands.
She hence arrived at Majuro on 1 August, where she discharged her cargo.
She headed for Pearl Harbor, where she was attached to the United States Third Fleet to store replacement aircraft to support the ongoing Mariana and Palau Islands campaign and the Philippines campaign.
Seventy-two planes were loaded onto Steamer Bay, and she sailed for Seeadler Harbor, Manus Island, arriving on 21 August.
Throughout the next two and a half months, she remained on station, providing replacement aircraft and crew for Task Group 38.
After completing her duties, she returned to Pearl Harbor, where she underwent repairs and training from 15 November to 5 December.

Steamer Bay departed back to Seeadler Harbor, arriving on 17 December.
There, she was assigned to Task Group 77.4 (Taffy 2), commanded by Rear Admiral Felix Stump, which had previously participated in the Battle of Leyte Gulf.
The task force consisted of six escort carriers and their escorts.
On 1 January 1945, the task force sortied out of Seeadler Harbor, in support of the Invasion of Lingayen Gulf.
En route, the escort carriers came under heavy aerial attacks.
Of the six carriers within Taffy 2, Ommaney Bay was sunk by a kamikaze plane on 4 January, and Manila Bay and Savo Island were damaged by additional kamikazes on 5 January.
Steamer Bay herself narrowly missed being hit, with a kamikaze once flying dangerously close to her stern.
Throughout the landings, the escort carrier task groups anchored offshore launched over 1,400 aircraft sorties in support of the operation.
In the middle of operations, Taffy 2 was reformed under Rear Admiral Felix Stump, partially because of the losses and damages suffered by the escort carriers.
In anticipation for possible Japanese counterattacks on American positions on Mindoro and Luzon, the task group proceeded south to operate in the waters offshore Mindoro.
Steamer Bay remained in the Philippine Islands with the rest of the 7th Fleet until 31 January, when she departed for Ulithi.

Steamer Bay was only anchored for five days, before she departed with the rest of the 5th Fleet, bound for Iwo Jima.
She was incorporated into Carrier Division 26, under the command of Rear Admiral Clifton Sprague, alongside four other escort carriers.
The task group began operations, 50 mi (80 km) west of Iwo Jima, on 16 February.
The task group's mission was to neutralize Japanese bases and positions along the Nanpō Islands until 19 February (D-Day).
The task group then provided close air support for the marines throughout the landings and the costly struggle throughout the island.

Steamer Bay, along with Anzio, was relieved on 7 March, and then proceeded to Leyte.
They arrived at San Pedro Bay on 12 March, where she prepared for the upcoming invasion of Okinawa Island.
She sailed for the Ryukyu Islands on 27 March, arriving in her operating area south of the island on the morning of 1 April.
Operations were complicated by uncooperative weather and choppy seas.
On 3 April, a sailor was cast overboard when a railing broke.
His body was not recovered.
She conducted operations until 26 May when she was relieved, and sailed to Apra Harbor, Guam, for repairs and rest.
On 10 June, she was ordered to join the 3rd Fleet east of Miyako Jima assisted her task group in neutralizing Japanese airfields on Sakishima Gunto.
She conducted air strikes against the airfields from 14 June to 22 June, before sailing for Ulithi.

Steamer Bay left Ulithi on 3 July, part of the Logistics Support Group, responsible for resupplying the fast carrier forces with aircraft during operations against the Japanese mainland.
On 20 July, she was det
After being commissioned, Steamer Bay conducted trials and went on a shakedown cruise down the West Coast, before arriving at San Diego. On 14 May, she sailed for the New Hebrides, transporting Marine Air Group (MAG) 61. She arrived at Espiritu Santo on 30 May, where her cargo was unloaded. She departed on 2 June, arriving at San Diego on 20 June. On 19 July, she loaded 298 marines and 72 aircraft, and proceeded westwards for the Marshall Islands. She hence arrived at Majuro on 1 August, where she discharged her cargo. She headed for Pearl Harbor, where she was attached to the United States Third Fleet to store replacement aircraft to support the ongoing Mariana and Palau Islands campaign and the Philippines campaign. Seventy-two planes were loaded onto Steamer Bay, and she sailed for Seeadler Harbor, Manus Island, arriving on 21 August. Throughout the next two and a half months, she remained on station, providing replacement aircraft and crew for Task Group 38. After completing her duties, she returned to Pearl Harbor, where she underwent repairs and training from 15 November to 5 December.
Steamer Bay departed back to Seeadler Harbor, arriving on 17 December. There, she was assigned to Task Group 77.4 (Taffy 2), commanded by Rear Admiral Felix Stump, which had previously participated in the Battle of Leyte Gulf. The task force consisted of six escort carriers and their escorts. On 1 January 1945, the task force sortied out of Seeadler Harbor, in support of the Invasion of Lingayen Gulf. En route, the escort carriers came under heavy aerial attacks. Of the six carriers within Taffy 2, Ommaney Bay was sunk by a kamikaze plane on 4 January, and Manila Bay and Savo Island were damaged by additional kamikazes on 5 January. Steamer Bay herself narrowly missed being hit, with a kamikaze once flying dangerously close to her stern. Throughout the landings, the escort carrier task groups anchored offshore launched over 1,400 aircraft sorties in support of the operation. In the middle of operations, Taffy 2 was reformed under Rear Admiral Felix Stump, partially because of the losses and damages suffered by the escort carriers. In anticipation for possible Japanese counterattacks on American positions on Mindoro and Luzon, the task group proceeded south to operate in the waters offshore Mindoro. Steamer Bay remained in the Philippine Islands with the rest of the 7th Fleet until 31 January, when she departed for Ulithi.
Steamer Bay was only anchored for five days, before she departed with the rest of the 5th Fleet, bound for Iwo Jima. She was incorporated into Carrier Division 26, under the command of Rear Admiral Clifton Sprague, alongside four other escort carriers. The task group began operations, 50 mi (80 km) west of Iwo Jima, on 16 February. The task group's mission was to neutralize Japanese bases and positions along the Nanpō Islands until 19 February (D-Day). The task group then provided close air support for the marines throughout the landings and the costly struggle throughout the island.
Steamer Bay, along with Anzio, was relieved on 7 March, and then proceeded to Leyte. They arrived at San Pedro Bay on 12 March, where she prepared for the upcoming invasion of Okinawa Island. She sailed for the Ryukyu Islands on 27 March, arriving in her operating area south of the island on the morning of 1 April. Operations were complicated by uncooperative weather and choppy seas. On 3 April, a sailor was cast overboard when a railing broke. His body was not recovered. She conducted operations until 26 May when she was relieved, and sailed to Apra Harbor, Guam, for repairs and rest. On 10 June, she was ordered to join the 3rd Fleet east of Miyako Jima assisted her task group in neutralizing Japanese airfields on Sakishima Gunto. She conducted air strikes against the airfields from 14 June to 22 June, before sailing for Ulithi.
Steamer Bay left Ulithi on 3 July, part of the Logistics Support Group, responsible for resupplying the fast carrier forces with aircraft during operations against the Japanese mainland. On 20 July, she was det
USS Steamer Bay