Buka Island is the second largest island in the Papua New Guinean province of Bougainville.

Buka was first occupied by humans in paleolithic times, some 30,000 years ago. The present inhabitants speak languages that in all likelihood stem from the eastward push of Austronesian languages of the so-called Lapita Culture complex, some 2,700 years ago.

The island was occupied by Japan during World War II. Although the island was strafed and bombed by allied airforces, allied armies never fought in Buka. The Japanese surrendered when the Allies were approaching the Selau peninsula in nearby Bougainville.

The economy of Buka can be divided into a very small urban component and the village sector. The village sector is characterised by subsistence farming, primarily of sweet potato as a staple, and the production of copra and cocoa as cash crops by family-sized units and small cooperative work groups. Vanilla and tropical spice crops have made a halting progress, and remain very minor sources of income for villagers.