Kailua is a census-designated place (CDP) in Hawaii County, Hawaii, United States, in the North Kona District of the Island of Hawaii. The population was 9,869 at the 2000 census. It is the center of commerce and of the tourist industry on West Hawaii. Its post office is designated Kailua-Kona to differentiate it from the larger Kailua located on windward Oahu, and it is sometimes referred to as "Kona" in everyday speech. The city is served by Kona International Airport, located just to the north in the adjacent Kalaoa CDP. Kailua-Kona was the closest major settlement to the epicenter of the 2006 Hawaii Earthquake.