Orkney (; Scots: Orkney; Old Norse: Orkneyjar; Norn: Orknøjar), also known as the Orkney Islands, is an archipelago in the Northern Isles of Scotland, situated off the north coast of the island of Great Britain. Orkney is 10 miles (16 km) north of the coast of Caithness and has about 70 islands, of which 20 are inhabited. The largest island, the Mainland, has an area of 523 square kilometres (202 sq mi), making it the sixth-largest Scottish island and the tenth-largest island in the British Isles. Orkney's largest settlement, and also its administrative centre, is Kirkwall.

Orkney is one of the 32 council areas of Scotland, as well as a constituency of the Scottish Parliament, a lieutenancy area, and an historic county. The local council is Orkney Islands Council, one of only three councils in Scotland with a majority of elected members who are independents.

The islands have been inhabited for at least 8,500 years, originally occupied by Mesolithic and Neolithic tribes and then by the Picts. Orkney was colonized and later annexed by the Kingdom of Norway in 875 and settled by the Norsemen. In 1472, the Parliament of Scotland absorbed the Earldom of Orkney into the Kingdom of Scotland, following failure to pay a dowry promised to James III of Scotland by the family of his bride, Margaret of Denmark.

In addition to the Mainland, most of the remaining islands are divided into two groups: the North Isles and the South Isles. The climate is relatively mild and the soils are extremely fertile; most of the land is farmed, and agriculture is the most important sector of the economy. The significant wind and marine energy resources are of growing importance; the amount of electricity that Orkney generates annually from renewable energy sources exceeds its demand.

The local people are known as Orcadians; they speak a distinctive dialect of the Scots language and have a rich body of folklore. Orkney contains some of the oldest and best-preserved Neolithic sites in Europe; the "Heart of Neolithic Orkney" is a designated UNESCO World Heritage Site. Orkney also has an abundance of marine and avian wildlife.