Norn is an extinct North Germanic language that was spoken in the Northern Isles (Orkney and Shetland) off the north coast of mainland Scotland and in Caithness in the far north of the Scottish mainland. After Orkney and Shetland were pledged to Scotland by Norway in 1468–69, it was gradually replaced by Scots. Norn is thought to have become extinct in 1850, after the death of Walter Sutherland, the language's last known speaker, though there are claims the language persisted as late as the 20th century.
Norse settlement in the islands probably began in the early 9th century. These settlers are believed to have arrived in very substantial numbers, and like those who migrated to Iceland and the Faroe Islands, it is probable that most came from the west coast of Norway. Shetland toponymy bears some resemblance to that of northwest Norway, while Norn vocabulary implies links with more southerly Norwegian regions.
Orkney and Shetland were pledged to James III in 1468 and 1469 respectively, and it is with these pledges that the replacement of Norn with Scots is most associated. However, the decline of Norse speech in Orkney probably began in 1379 when the Earldom of Orkney, covering all of the Northern Isles, passed into the hands of Henry Sinclair, of Clan Sinclair. Scots had superseded Norse as the language of prestige on Orkney by the early 15th century.
In Shetland, the transition began later, but by the end of the 15th century both island groups were bilingual. Despite this, the process by which Scots overtook Norn as the primary spoken language on the islands was not a swift one, and most natives of Orkney and Shetland probably spoke Norn as a first language until the late 16th and early-to-mid 17th centuries respectively. One of the last documents written in Norn was for a 1597 mortgage issued over a property belonging to Else, sister of Anna Throndsen, who had married a Shetland man Andrew Mowat of Heogoland in Eshaness.
It is not known exactly when Norn became extinct.