In January 1942, "Itsukushima" was assigned to the Netherlands East Indies theatre of operations, supporting the Japanese invasions of Tarakan and Balikpapan in Borneo as flagship of the Second Base Unit under Admiral Sueto Hirose. From 10 March, she was reassigned to the 3rd Southern Expeditionary Fleet under Admiral Rokuzō Sugiyama, and continued to support operations in Borneo and Java. She was then reassigned to the Second Southern Expeditionary Fleet, under the Southwest Area Fleet, patrolling between Singapore, Surabaya, Batavia and Ambon to the end of the year. On 25–26 December 1942, together with the light cruiser , "Itsukushima" landed troops of the 24th Naval Base force which captured Hollandia, New Guinea.