Juist is an island and municipality in the district of Aurich in Lower Saxony in Germany. The island is one of seven East Frisian Islands at the edge of the Lower Saxon Wadden Sea in the southern North Sea. It is located between Borkum Island (west), Memmert Island (southwest) and Norderney (east). The island is 17 km (11 mi) long and from 500 metres (1,600 ft) to 1 kilometre (0.62 mi) wide, depending on the tide levels. There are two villages on the island: the main village Juist, and Loog. The island is separated from Norderney by the Norderneyer Seegatt.

The East Frisian Islands are a chain of islands in the North Sea, off the coast of East Frisia in Lower Saxony, Germany. The islands extend for some 90 kilometres (56 mi) from west to east between the mouths of the Ems and Jade / Weser rivers and lie about 3.5 to 10 km offshore. Between the islands and the mainland are extensive mudflats, known locally as Watten, which form part of the Wadden Sea. In front of the islands are Germany's territorial waters, which occupy a much larger area than the islands themselves. The islands, the surrounding mudflats and the territorial waters form a close ecological relationship. The island group makes up about 5% of the Lower Saxony Wadden Sea National Park.