Chesterfield Islands, group of coral islands in the French overseas country of New Caledonia, southwestern Pacific Ocean. The group comprises 11 well-wooded islets, none of which exceeds 1.5 miles (2.5 km) in length. The main islands are Long, Bampton, Reynard, Loop, and Avon islands, and the Three Islands of Mouillage. The Chesterfields have rich guano deposits, which have not been worked since 1921. There are no permanent inhabitants.