Saipan, island, Commonwealth of the Northern Mariana Islands, in the western Pacific Ocean. It is the second-largest of the Mariana Islands, with an area of about 122 sq km (47 sq mi). Tanapeg, the chief town, is located on the western side of the island. The principal industry of Saipan is the cultivation of sugar cane. Coconuts, coffee, and tropical fruits are also grown and exported. The population (1990) is 38,896.

During World War II, the island was captured by United States forces in 1944, and it was used as a base for air attacks against the Japanese mainland. After the war until 1986, it was part of the US-administered United Nations Trust Territory of the Pacific Islands.