Noss is separated from the island of Bressay by the narrow Noss Sound. It has been run as a sheep farm since 1900.
Noss had a population of 20 in 1851 but has had no permanent inhabitants since 1939. The main focus of settlement on Noss was around the low lying west side of the island at Gungstie (Old Norse: a landing place). Gungstie was built in the 1670s and is currently used by the seasonal wildlife wardens. Another settlement at Setter, on the south east of the island was inhabited until the 1870s and now lies derelict. Among the few families living on Noss were the Booth family headed by Joseph Booth (1765–1847). Genealogical records indicate that he was occupied as a farmer and fish curer. Records show that he was resident on Noss as early as 1834.
Noss was designated a National Nature Reserve in 1955 and is managed by Scottish Natural Heritage (SNH).The island is linked to Bressay by a seasonal ferry service, run by the wildlife wardens using an inflatable boat.
Noss is renowned for its seabird colonies and is one of the more accessible of the internationally important seabird colonies in the North Atlantic. Attractions on Noss include a visitor centre, the Pony Pund built to breed Shetland ponies, the Holm of Noss rock and the Noup cliff. The sandstone cliffs of Noss have weathered into a series of horizontal ledges making ideal breeding grounds for gannets, puffins, guillemots, shags, black-legged kittiwakes, razorbills, fulmars and great skuas. Otters are also frequently seen around the island.
As well as a National Nature Reserve, Noss also holds two other designations for its important wildlife, including: