The Nore is a sandbank at the mouth of the Thames Estuary, England, near Sheerness.
From 1732 the Nore lightship, the first lightship in the world, marked the sandbank: placed there as an experiment by Robert Hamblin, its patentee. Small wooden ships, often Dutch-built galliots, served as the early Nore lightships. By the end of the 19th century a larger ship with a revolving light had appeared, but after about 1915 the authorities abandoned the lightship. Sea Reach No. 1 Buoy now marks the anchorage-point of the former lightship, about mid-way between Shoeburyness in Essex and the Isle of Sheppey in Kent. This ranks as the limit of the Thames and the beginning of the North Sea.
In May/June 1797 the anchorage adjoining the Nore witnessed a mutiny in the British Royal Navy fleet then lying here, known as the Mutiny of the Nore.
The Royal Navy from 1899 to 1955 maintained the position of Commander-in-Chief at the Nore, a senior officer with responsibility for protection of the entrance to the port of London as well as merchant traffic up and down the east coast of Britain.