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.

The Lower Saxon Wadden Sea National Park was established in 1986 and embraces the East Frisian Islands, mudflats and salt marshes between the Bay of Dollart on the border with the Netherlands in the west and Cuxhaven as far as the Outer Elbe shipping channel in the east. The national park has an area of about 345,800 hectares (1,335 sq mi). The National Park organisation is located in Wilhelmshaven. In June 2009, the National Park became a UNESCO World Heritage Site along with the Schleswig-Holstein Wadden Sea and the Dutch Wadden Sea, highlighting its unique intertidal ecosystem and high biodiversity.