The Mariana and Palau Islands campaign, also known as Campaign Plan Granite II, was an offensive launched by United States forces against Imperial Japanese forces in the Pacific Ocean between June and November 1944 during the Pacific War. The campaign consisted of Operation Forager, which captured the Mariana Islands, and Operation Statemate, which captured Palau. Operation Causeway, the invasion of Taiwan was also planned but not executed. The offensive, under the overall command of Chester W. Nimitz, followed the Gilbert and Marshall Islands campaign and was intended to neutralize Japanese bases in the central Pacific, support the Allied drive to retake the Philippines, and provide bases for a strategic bombing campaign against Japan.

The Mariana Islands, also simply the Marianas, are a crescent-shaped archipelago comprising the summits of fourteen longitudinally oriented, mostly dormant volcanic mountains in the northwestern Pacific Ocean, between the 12th and 21st parallels north and along the 145th meridian east. They lie south-southeast of Japan, west-southwest of Hawaii, north of New Guinea and east of the Philippines, demarcating the Philippine Sea's eastern limit. They are found in the northern part of the western Oceanic sub-region of Micronesia, and are politically divided into two jurisdictions of the United States: the Commonwealth of the Northern Mariana Islands and, at the southern end of the chain, the territory of Guam. The islands were named after the influential Spanish queen Mariana of Austria following their colonization in the 17th century.