The Coromandel Peninsula on the North Island of New Zealand extends 85 kilometres (53 mi) north from the western end of the Bay of Plenty, forming a natural barrier protecting the Hauraki Gulf and the Firth of Thames in the west from the Pacific Ocean to the east. It is 40 kilometres (25 mi) wide at its broadest point. Almost its entire population lives on the narrow coastal strips fronting the Hauraki Gulf and the Bay of Plenty. In clear weather the peninsula is clearly visible from Auckland, the country's biggest city, which lies on the far shore of the Hauraki Gulf, 55 kilometres (34 mi) to the west. The peninsula is part of the Thames-Coromandel District and the Waikato Region.

The North Island, also officially named Te Ika-a-Māui, is one of the two main islands of New Zealand, separated from the larger but less populous South Island by Cook Strait. With an area of 113,729 km2 (43,911 sq mi), it is the world's 14th-largest island, constituting 43% of New Zealand's land area. It has a population of 3,997,300, which is 77% of New Zealand's residents, making it the most populous island in Polynesia and the 28th-most-populous island in the world.