Belitung is an island on the east coast of Sumatra, Indonesia in the Java Sea. It covers 4,859 km2 (1,876.1 sq mi), and had a population of 309,097 at the 2020 Census; the official estimate as at mid 2023 was 320,500. Administratively, it forms two regencies within the province of Bangka-Belitung Islands. The island is known for its pepper and for its tin. It was in the possession of the United Kingdom from 1812 until Britain ceded control of the island to the Netherlands in the Anglo-Dutch Treaty of 1824. Its main town is Tanjung Pandan. The United Nations Educational, Scientific and Cultural Organization has declared 17 tourist attractions in the Belitung Geopark as world geoparks.

The Java Sea is an extensive shallow sea on the Sunda Shelf, between the Indonesian islands of Borneo to the north, Java to the south, Sumatra to the west, and Sulawesi to the east. Karimata Strait to its northwest links it to the South China Sea. It is a part of the western Pacific Ocean.