Kailua is a census-designated place (CDP) in Honolulu County, Hawaii, United States. It lies in the Koʻolaupoko District of the island of Oʻahu on the windward coast at Kailua Bay. It is in the judicial district and the ahupua’a named Ko’olaupoko. It is 12 miles (19 km) northeast of Honolulu – over Nu‘uanu Pali. The population was 38,635 at the 2010 census.
In the Hawaiian language Kailua means “two seas” or “two currents”, a contraction of the words kai (meaning “sea” or “sea water”) and ʻelua (meaning “two”); it is so named because of the two lagoons in the district or the two currents which run through Kailua Bay.
Kailua is primarily a residential community, with a centralized commercial district along Kailua Road. The population was 50,000 in 1992.
Places of note in Kailua include Kailua Beach Park, Lanikai Beach, Kawai Nui Marsh, Maunawili Falls, and Marine Corps Base Hawaii.
During the reign of King Kākuhihewa and his successors, Kanekapu, Kahoowaha, Kauakahiakahoowaha, and Kualiʻi, Kailua replaced Waikiki as the residential seat of the Oʻahu Rulers (aliʻi nui of Oʻahu). Many ancient temple ruins, such as those at Ulupo Heiau State Historic Site, are in the area.
Kailua Beach is crescent-shaped, about 2.5 miles (4.0 km) long, and ranging between 50 and 150 feet (15 and 46 m) wide. The ocean bottom fronting the beach slopes gently to overhead depths without any coral heads. Light to medium waves support surfing and bodysurfing. The steady trade winds make Kailua Beach a top windsurfing and kitesurfing destination. Robby Naish, first World Champion of windsurfing and Professional Windsurfers Association Hall of Fame inductee, grew up in Kailua.
Sea kayaking and stand-up paddleboarding to the protected seabird sanctuaries Flat Island and the Nā Mokulua, popularly known as “the Mokes”, have become increasingly popular water activities at the beach.
Kailua is located at 21°23′51″N 157°44′22″W (21.397370, −157.739515). Nearby towns include Kāneʻohe, Maunawili, and Waimānalo.
According to the United States Census Bureau, the CDP has a total area of 10.6 square miles (27.4 km2). 7.8 square miles (20.1 km2) of it is land, and 2.8 square miles (7.3 km2) of it (26.62%) is water. A significant portion of this water area is Kawai Nui Marsh, the largest wetland in the Hawaiian Islands and a nominated Ramsar Convention site.