Daru Island is elliptical in shape, with dimensions of 5.0 by 3.7 kilometers, an area of 14.7 km2, and an elevation of up to 27 m. The island is separated from the mainland in the north, specifically the mouth of Oriomo River, by the 3.5 km wide Daru Roads.

The island has an international airport which is mainly used by Australian aircraft chartered by mining companies for customs clearance or to pick up jet fuel.

The first recorded sighting by Europeans was by the Spanish expedition of Luís Vaez de Torres on 5 September 1606.

[1] The island's airport was used to refuel Allied aircraft during World War II and seaplanes operated from nearby waters.

[2] In 2020 the PNG Government signed a memorandum of understanding with the Chinese Fujian Zhonghong Fishery Company which intends to build a "comprehensive multi-functional fishery industrial park" on the island.