Sikaiana formerly called Stewart Islands is a small atoll 212 km NE of Malaita. It is almost 14 km in length and its lagoon, known as Te Moana, is totally enclosed by the coral reef. Its total land surface is only 2 km². There is no safe anchorage close to this atoll, which makes it often inaccessible.

Sikaiana is located Latitude: 8° 25' 0 South and Longitude: 162° 52' 0 East. The main island, located at the easternmost corner, is called Sikaiana. The three small islands in the west of the atoll are Tehaolei, Matuiloto and Matuavi. There are also two artificial islands on the reef, Te Palena and Hakatai'atata.

Administratively Sikaiana is an outlying region of Malaita Province in the Solomon Islands. Sikaiana's population is approximately 300 people of Polynesian descent. In 1856, when Hawai‘i was offered the sovereignty of Sikaiana, the Privy Council voted to accept the cession. King Kamehameha IV approved the action, making Hawai‘i an imperial power of sorts. But there were second thoughts. The great distance of the atoll from Honolulu would make administration impossible, and the cession was never formalized. Some residents have claimed to be native Hawaiians and citizens of the United States. According to these residents, the Stewart Islands were given to King Kamehameha IV in 1856, and therefore the islands were part of the Kingdom of Hawai‘i at the time of the United States' annexation in 1898. The United States disagrees, arguing that the 1898 law annexed only the "Hawaiian Islands and their dependencies", and that the law defined dependencies as the islands named by a report by the Hawaiian Commission that omitted the Stewart Islands. Some residents applied to register to vote in Hawai‘i in 1996, but their applications were turned down by the Hawaiian Sovereignty Election Council.