Guadalcanal (Isatabu) is a tropical island in the South-Western Pacific. The largest island in the Solomons, it was discovered by the Spanish expedition of Alvaro de Mendaña in 1568. The name comes from Guadalcanal, a village in the province of Seville, in Andalusia, Spain, birthplace of Pedro de Ortega Valencia, a member of Mendaña's expedition.

During 1942-43 it was the scene of bitter fighting between Japanese and Americans in which the latter were victorious.

At the end of the war, Honiara, on the north coast of Guadalcanal, became the new capital of the British Solomon Islands Protectorate. Guadalcanal is mainly covered in tropical rainforest and jungle, and it has a mountainous interior with an active volcano, Mount Popomanaseu. The population in 1998 was around 85,000.

A Spanish expedition from Peru under the command of Álvaro de Mendeña de Neira discovered the island in the year 1568. Mendaña's subordinate, Pedro de Ortega Valencia, named the island after his home town Guadalcanal in Andalusia, Spain. The name comes from the Arabic Wādî al-Khānātوادي القنا, which means "Valley of the Stalls" or "River of Stalls", referring to the refreshment stalls which were set up there during Muslim rule in Andalusia. In the years that followed the discovery, the island was variously referred to as Guadarcana, Guarcana, Guadalcana, and Guadalcanar.