Solomon Islands (country), constitutional monarchy and member of the Commonwealth of Nations, consisting of about 30 islands and numerous atolls in the South Pacific Ocean, east of New Guinea. The country includes most of the Solomon Islands group, notably Guadalcanal, New Georgia, Santa Isabel, Malaita, Choiseul, San Cristobal (Makira), and Vella Lavella, as well as Ontong Java (Lord Howe) Atoll, Rennell, and the Santa Cruz Islands. The total area is 27,556 sq km (10,639 sq mi).