Honolulu ( HON-ə-LOO-loo; Hawaiian: [honoˈlulu]) is the capital and most populous city of the U.S. state of Hawaii, which is in the Pacific Ocean. An unincorporated city, it is the county seat of the consolidated City and County of Honolulu, situated along the southeast coast of the island of Oʻahu, and is the westernmost and southernmost major U.S.

city. Honolulu is Hawaii's main gateway to the world. It is also a major hub for business, finance, hospitality, and military defense in both the state and Oceania. The city is characterized by a mix of various Asian, Western, and Pacific cultures, reflected in its diverse demography, cuisine, and traditions. Honolulu is Hawaiian for "sheltered harbor" or "calm port"; its old name, Kou, roughly encompasses the area from Nuʻuanu Avenue to Alakea Street and from Hotel Street to Queen Street, which is the heart of the present downtown district.

The city's desirability as a port accounts for its historical growth and importance in the Hawaiian archipelago and the broader Pacific region. Honolulu has been the capital of the Hawaiian Islands since 1845, firstly of the independent Hawaiian Kingdom, and since 1898 of the U.S. territory and state of Hawaii.

The city gained worldwide recognition following the Empire of Japan's attack on nearby Pearl Harbor on December 7, 1941, which prompted the entry of the U.S. into World War II; the harbor remains a major U.S. Navy base, hosting the United States Pacific Fleet, the world's largest naval command. Hawaii is the only state with no incorporated places below the county level.

The U.S. Census Bureau recognizes the approximate area commonly referred to as the "City of Honolulu" as the Urban Honolulu census-designated place. As of the 2020 U.S. Census, the population of Honolulu was 350,964. The Urban Honolulu Metropolitan Statistical Area had 1,016,508 residents in 2020. With over 300,000 residents, Honolulu is the most populous Oceanian city outside Australasia. Honolulu's favorable tropical climate, rich natural scenery, and extensive beaches make it a popular global destination for tourists.

With over 711,000 visitors as of 2022, Honolulu is the tenth-most visited city in the United States after New York City, Miami, Orlando, Los Angeles, San Francisco, Las Vegas, Washington, D.C., Chicago, and Boston.