From Wikipedia, the free encyclopedia. Lanai City is a census-designated place (CDP) on the island of Lanai, in Maui County, Hawaii, United States. The population was 3,102 at the 2010 census. Because of the island of Lanai's small population, Lanai City functions as the island's main commerce and business area. Many of the island's restaurants and shops can be found in the town square that surrounds Dole Park.