After operational training in southern Californian waters, Portland steamed for the Aleutians late in May, arriving on 11 June and bombarding Kiska on 26 July.
After covering a reconnaissance landing on Little Kiska on 17 August, she called at Pearl Harbor on 23 September, there to San Francisco in early October, then back to Pearl Harbor in mid-October.
From November 1943 to February 1944, Portland participated in the Gilbert and Marshall Islands campaigns.
She bombarded Tarawa on 20 November supporting landings there for several days.
She was lightly damaged by a friendly depth charge when a nearby destroyer erroneously detected a Japanese submarine.
In December 1943 she moved to the Marshall Islands escorting the new Essex-class carrier Lexington.
While Lexington came under air attack, none of the Japanese planes came within range of Portland and she did not open fire.
She returned to Pearl Harbor on 25 December, and went into drydock to repair her rudder and propellers.

After repairs, she joined Task Group 51 under Rear Admiral Harry W. Hill for an attack on Darrit, steaming for that island on 23 January and arriving 30 January.
After shelling the island for 30 minutes, it was discovered no Japanese were ashore.
She then moved to support operations on Eniwetok Atoll on 8 February, providing shore bombardment on Parry Island ahead of landings which took place on 19 February.
She then screened carriers conducting airstrikes at Palau, Yap, Ulithi, and Woleai between 30 March and 1 April.
She then joined with a carrier force assigned to cover the landings around Hollandia and Tanahmerah on New Guinea, which took place from 21–24 April.
She steamed northward with the carrier force and struck Truk with five other cruisers and destroyers.
Portland then bombarded Satawan in the Nomei Group.
Following this series of operations, Portland returned to Mare Island for a more extensive overhaul, which was completed in August.
She returned to the western Pacific for shore bombardments of Peleliu from 12–14 September.
The cruiser supported the landing on Peleliu on 15 September, providing artillery to support the advance of Allied forces.
She provided gunfire support at Peleliu through 29 September, and then steamed for Seeadler Harbor, Manus Island in the Admiralties.
After operational training in southern Californian waters, Portland steamed for the Aleutians late in May, arriving on 11 June and bombarding Kiska on 26 July. After covering a reconnaissance landing on Little Kiska on 17 August, she called at Pearl Harbor on 23 September, there to San Francisco in early October, then back to Pearl Harbor in mid-October. From November 1943 to February 1944, Portland participated in the Gilbert and Marshall Islands campaigns. She bombarded Tarawa on 20 November supporting landings there for several days. She was lightly damaged by a friendly depth charge when a nearby destroyer erroneously detected a Japanese submarine. In December 1943 she moved to the Marshall Islands escorting the new Essex-class carrier Lexington. While Lexington came under air attack, none of the Japanese planes came within range of Portland and she did not open fire. She returned to Pearl Harbor on 25 December, and went into drydock to repair her rudder and propellers.
After repairs, she joined Task Group 51 under Rear Admiral Harry W. Hill for an attack on Darrit, steaming for that island on 23 January and arriving 30 January. After shelling the island for 30 minutes, it was discovered no Japanese were ashore. She then moved to support operations on Eniwetok Atoll on 8 February, providing shore bombardment on Parry Island ahead of landings which took place on 19 February. She then screened carriers conducting airstrikes at Palau, Yap, Ulithi, and Woleai between 30 March and 1 April. She then joined with a carrier force assigned to cover the landings around Hollandia and Tanahmerah on New Guinea, which took place from 21–24 April. She steamed northward with the carrier force and struck Truk with five other cruisers and destroyers. Portland then bombarded Satawan in the Nomei Group. Following this series of operations, Portland returned to Mare Island for a more extensive overhaul, which was completed in August. She returned to the western Pacific for shore bombardments of Peleliu from 12–14 September. The cruiser supported the landing on Peleliu on 15 September, providing artillery to support the advance of Allied forces. She provided gunfire support at Peleliu through 29 September, and then steamed for Seeadler Harbor, Manus Island in the Admiralties.
USS Portland (CA-33)