Neuwerk (; is a 3 km2 tidal island in the Wadden Sea a marginal part of North Sea along the German coast. The population in 2021 was 30. Neuwerk is located 13 km northwest of Cuxhaven, between the Weser and Elbe estuaries. The distance to the centre of Hamburg is about 120 km.

A tidal island is a raised area of land within a waterbody, which is connected to the larger mainland by a natural isthmus or man-made causeway that is exposed at low tide and submerged at high tide, causing the land to switch between being a promontory/peninsula and an island depending on tidal conditions.