Unst (//; Scots: Unst; Norn: Ønst) is one of the North Isles of the Shetland Islands, Scotland. It is the northernmost of the inhabited British Isles and is the third-largest island in Shetland after Mainland and Yell. It has an area of 46 sq mi (120 km2).
|Old Norse name||Ǫmstr|
|Meaning of name||Possibly pre-Celtic|
|OS grid reference|
|Highest elevation||Saxa Vord, 284 m (932 ft)|
|Sovereign state||United Kingdom|
|Council area||Shetland Islands|
|Population density||5.2 people/km²|
Unst is largely grassland, with coastal cliffs. Its main village is Baltasound, formerly the second-largest herring fishing port after Lerwick and now the location of a leisure centre and the island's airport. Other settlements include Uyeasound, home to Greenwell's Booth (a Hanseatic warehouse) and Muness Castle (built in 1598 and sacked by pirates in 1627); and Haroldswick, location of a boat museum and a heritage centre.