island, one of the Mariana Islands, part of the Northern Mariana Islands, a commonwealth of the United States, in the western Pacific Ocean. Saipan served as headquarters of the U.S.-administered United Nations Trust Territory of the Pacific Islands (Pacific Islands, Trust Territory of the) from 1962 to 1986. The island is hilly, rising to an elevation of 1,545 feet (471 metres) at Mount Takpochao (or Tagpochau); it is 14 miles (23 km) long and 5 miles (8 km) across at its widest point. Broad inlets (Laolao 【Magicienne】 Bay and Tanapag Harbor) are on both its sides. The smaller island of Tinian lies immediately southwest across the Saipan Channel.

Saipan was under Spanish sovereignty from 1565 to 1899 and came under German rule from 1899 to 1914. It was made a Japanese mandate in 1920. During World War II, the successful U.S.-led Allied invasion and capture of the island (June–July 1944) was one of the fiercest land battles in the Pacific theatre. Some 3,500 U.S. troops died in the fighting, and nearly all of the 30,000 Japanese defenders were killed; thousands of Japanese civilians also died, many jumping to their deaths off Banzai Cliff, at the northern end of the island, rather than face capture. Saipan became an important U.S. military air base during the last year of the war, and between 1953 and 1962 it was under U.S. naval jurisdiction.