[honoˈlulu]) is the state capital and the most populous city in the U.S. state of Hawaii. It is the county seat of the City and County of Honolulu. Hawaii is a major tourist destination and Honolulu, situated on the island of Oahu, is the main gateway to Hawaii and a major gateway into the United States.hese indicate that there was a settlement where Honolulu now stands in the 11th century. However, after Kamehameha I conquered Oʻahu in the Battle of Nuʻuanu at Nuʻuanu Pali, he moved his royal court from the Island of Hawaiʻi to Waikīkī in 1804. His court relocated in 1809 to what is now downtown Honolulu.