Hanson Bay is a large bay which comprises almost the entire east coast of Chatham Island/Rekohu, the largest island in New Zealand's Chatham Islands archipelago. It is 35 kilometres in extent, stretching from Okawa Point in the island's northeast to Manukau Point in the southeast.

The Chatham Islands sit on the Chatham Rise, a large, relatively shallowly submerged (no more than 1,000 metres deep)#160;reach of the Zealandia continent. The Chatham Islands are 800 kilometres east of New Zealand's South Island in the Pacific Ocean. The islands are generally hilly with the coasts a varied mixture including cliffs and sand dunes, beaches and lagoons. Chatham and Pitt are the only inhabited islands, with the remaining smaller islands being conservation reserves with access restricted or prohibited. The livelihoods of the inhabitants depend mainly on agriculture, fishing and tourism.