Laysan is one of the Northwestern Hawaiian Islands, located 808 nautical miles northwest of Honolulu. It comprises one land mass of 1,016 acres (4.11 km2), about 1 by 1+1⁄2 miles in size. It is an atoll of sorts, although the land completely surrounds a shallow central lake some 2.4 m (7.9 ft) above sea level that has a salinity approximately three times greater than the ocean. Laysan's Hawaiian name, Kauō, means 'egg'.

The Laysan finch is a species of Hawaiian honeycreeper, that is endemic to the Northwestern Hawaiian Islands. It is one of four remaining finch-billed Hawaiian honeycreepers and is closely related to the smaller Nihoa finch. The Laysan finch is named for Laysan, the island to which it was endemic on its discovery. It was subsequently introduced to a few other atolls, and its historical range included some of the main islands.