There are four main population centres, the islands of Namu, Majkin, Loen and Mae.

[2] The Spanish expedition of Álvaro de Mendaña made the first recorded sighting by Europeans of Namu Atoll on 17 September 1568.

A landing party found a chisel made of a nail and pieces of rope which were presumably gifts left there on 3 July 1566 by the galleon San Jerónimo, then commanded by the rebel pilot Lope Martín.

[3] Captain Thomas Dennet of the British vessel Britannia sighted the atoll in 1797 on route from Australia to China and named it Ross Island.

[4] The German Empire claimed Namu Atoll along with the rest of the Marshall Islands in 1885.