Lānaʻi (/ləˈnaɪ/; Hawaiian: [laːˈnɐʔi] or [naːˈnɐʔi]) is the sixth-largest of the Hawaiian Islands and the smallest publicly accessible inhabited island in the chain. It is also known as Pineapple Island because of its past as an island-wide pineapple plantation. The island's only settlement of note is the small town of Lānaʻi City. As of 2012, the island is 98% owned by Larry Ellison (CEO of Oracle), with the remaining 2% owned by the State of Hawaii.

Lānaʻi is somewhat comma-shaped with a width of 18 miles (29 km) in the longest direction. The land area is 140.5 square miles (364 km), making it the 42nd largest island in the United States. It is separated from the island of Molokaʻi by the Kalohi Channel to the north, and from Maui by the ʻAuʻau Channel to the east. The United States Census Bureau defines Lānaʻi as Census Tract 316 of Maui County. Its total population shrank from 3,193 as of the 2000 census to 3,102 as of 2010. Many of the island's landmarks are accessible only by dirt roads that require a four-wheel drive vehicle.

There is one school, Lanai High and Elementary School, serving the entire island from kindergarten through 12th grade. There are no traffic lights on the island.