Nelson is a New Zealand city on the eastern shores of Tasman Bay at the top of the South Island. It is the oldest city in the South Island and the second-oldest settled city in New Zealand; it was established in 1841 and became a city by royal charter in 1858.

The South Island, also named Te Waipounamu in Māori, is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman Sea, and to the south and east by the Pacific Ocean. The South Island covers 150,437 square kilometres (58,084 sq mi), making it the world's 12th-largest island, constituting 56% of New Zealand's land area. At low altitude, it has an oceanic climate.