The name comes from the village of Guadalcanal, in the province of Seville, in Andalusia, Spain, birthplace of Pedro de Ortega Valencia, a member of Mendaña's expedition.

Mendaña's subordinate, Pedro de Ortega Valencia, named the island after his home town Guadalcanal in Andalusia, Spain.

[3] In the years that followed the discovery, the island was variously referred to as Guadarcana, Guarcana, Guadalcana, and Guadalcanar, which reflected different pronunciations of its name in Andalusian Spanish.

Beginning during the 1860s, about 60,000 natives from many parts of the Solomon Islands were indentured and sent to Australia or Fiji by British authorities to work on plantations.

The Japanese then began to expand into the western Pacific, occupying many islands in an attempt to build a defensive ring around their conquests and threaten the lines of communication from the United States to Australia and New Zealand.

When an American reconnaissance mission spotted construction of a Japanese airfield at Lunga Point on the north coast of Guadalcanal, the situation became critical.

[5] This new Japanese airfield represented a threat to Australia, so as a matter of urgency, despite not being adequately prepared, the United States conducted its first amphibious landing of the war on Guadalcanal.

So many ships from both sides were sunk in the many naval engagements in and around the Solomon Island chain that the nearby waters came to be referred to as Ironbottom Sound.

During the engagement, the United States Navy intercepted and defeated a Japanese formation of ships on their way down "the Slot" to reinforce and resupply troops on the island, suffering losses of their own in the process.

Two U.S. Navy ships have been named for the campaign: To date, the only U.S. Coast Guardsman recipient of the Medal of Honor is Signalman 1st Class Douglas Albert Munro, awarded posthumously for his extraordinary heroism on 27 September 1942 at Point Cruz.

In 1952, the high commissioner for the Western Pacific moved from Fiji to Honiara, and the post was combined with that of the governor of the Solomon Islands.

[8] In early 1999, long-simmering tensions between the local Guale people on Guadalcanal and more recent migrants from the neighbouring island of Malaita erupted into violence.

The Guadalcanal Revolutionary Army, later called Isatabu Freedom Movement, began terrorising Malaitans in the rural areas of the island in an effort to force them out of their homes.

About 25 km (15 mi) from Honiara to the west, Vilu War Museum houses an outdoor collection of remains of various parts of military equipment and of several aircraft.

At 376,146 ha (1,452 sq mi), it covers some 70% of the island, extending along the southern coast inland to the central highlands, and contains riverine and lowland tropical rainforest, as well as the greatest contiguous area of cloud forest in the Solomons.