Nukunonu, formerly known as Duke of Clarence Island, is the largest atoll in Tokelau, a dependency of New Zealand located in the South Pacific Ocean. The atoll consists of approximately 30 islets surrounding a central lagoon.
The land area of Nukunonu covers about 5.5 km2 (2.1 sq mi), while its lagoon has a surface area of 109 km2 (42 sq mi). Of the various islets, Motuhaga is the only one with inhabitants, and the atoll has an estimated population of 531 people.