Kailua is a census-designated place (CDP) 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. 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 the larger Kailua located on windward Oʻahu, 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 Hawaiʻi Earthquake.
The community was established by King Kamehameha I to be his seat of government when he was chief of Kona before he consolidated rule of the archipelago, and it later it became the capital of the newly unified Kingdom of Hawaiʻi. The capital later moved to Lāhainā, then, to Honolulu. Royal fishponds at Kaloko-Honokōhau National Historical Park were the hub of unified Hawaiian culture. The town later functioned as a retreat of the Hawaiian royal family. Up until the late 1900s, Kailua-Kona was primarily a small fishing village. In the late 20th and early 21st centuries the region has undergone a real estate and construction boom fueled by tourism and investment.