Kailua is an unincorporated city (Census Designated Place) in Hawaiʻi County, Hawaii, United States, in the North Kona District of the Island of Hawaiʻi. The population was 11,975 at the 2010 census, up from 9,870 at the 2000 census. It is the center of commerce and of the tourist industry on West Hawaiʻi. Its post office is designated Kailua-Kona to differentiate it from Kailua located on the windward side of Oʻahu island, 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 Kiholo Bay earthquake.
Kailua-Kona is located at 19°39′0″N 155°59′39″W / 19.65000°N 155.99417°W / 19.65000; -155.99417 (19.649973, −155.994028), along the shoreline of Kailua Bay and up the southern slope of Hualālai volcano. There are no major rivers or streams in Kailua-Kona or on the Kona side of Hawaii.
According to the United States Census Bureau, the City has a total area of 39.9 square miles (103.3 km), of which 35.6 square miles (92.3 km) are land and 4.2 square miles (11.0 km), or 10.67%, are water.
Kailua-Kona is bordered to the north by Kalaoa, to the south by Holualoa, and to the west by the Pacific Ocean from Kailua Bay in the south to Honokohau Bay in the north. The Kailua-Kona postal code is 96740 (post office boxes – 96745).
As of the census of 2000, there were 9,870 people, 3,537 households, and 2,429 families residing in Kailua-Kona. The population density was 278.0 people per square mile (107.3/km²). There were 4,322 housing units at an average density of 121.7 per square mile (47.0/km²). The racial makeup of the City was 38.7% White, 0.5% Black or African American, 0.5% Native American, 18.3% Asian, 13.2% Pacific Islander, 1.9% from other races, and 27.07% from two or more races. 10.2% of the population were Hispanic or Latino of any race.
There were 3,537 households out of which 35.0% have children under the age of 18 living with them, 49.6% were married couples living together, 13.6% had a female householder with no husband present, and 31.3% were non-families. 22.6% of all households were made up of individuals and 7.2% had someone living alone who was 65 years of age or older. The average household size was 2.78 and the average family size was 3.26.
In Kailua-Kona the population was spread out with 27.3% under the age of 18, 9.0% from 18 to 24, 28.8% from 25 to 44, 24.9% from 45 to 64, and 10.0% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 98.8 males. For every 100 females age 18 and over, there were 95.8 males.
The median income for a household in the city was $40,874, and the median income for a family was $46,657. Males had a median income of $30,353 versus $26,471 for females. The per capita income for the CDP was $20,624. 10.8% of the population and 6.5% of families were below the poverty line. Out of the total population, 11.9% of those under the age of 18 and 3.9% of those 65 and older were living below the poverty line.
Kailua-Kona Hawaii neighborhoods include: Alii Heights, Hao-Kuni, Holualoa, Honalo, Kailua Kona, Kailua Park, Kaiminani, Kealakehe, Keauhou Akahi, Keauhou Estates, Keauhou Punahele Condos, Kilohana Kai, Kohanaiki Homestead, Komohana Kai, Kona Acres Palisades, Lokahi Makai, Pualani Estates, Pulani Estates II, Seascape