Mainland effectively provides the core of the Orkney Islands, linking the northern members of the archipelago with the southern ones.

Firth, Orphir, Stenness and Harray lie west of Kirkwall and east of the westernmost parishes.

A 2020 report states that "over the last 20 years there has been a growth in ... manufacturing, tourism, food and drink processing and, more recently, renewable energy".

A September 2020 report stated that "The Highlands and Islands region has been disproportionately impacted by the COVID-19 pandemic to date, when compared to Scotland and the UK as a whole".

The industry required short-term support for "business survival and recovery" and that was expected to continue as the sector was "severely impacted for as long as physical distancing and travel restrictions".

Kirkwall, the capital of the islands, is on the isthmus between west Mainland and east Mainland, which historically enabled it to have highly active harbours facing in two directions for the southern and northern Orkney Islands; the southern one, Scapa Flow, is a large, calm and immediately ocean-accessible natural harbour.

The old town is clustered along the main street, flanked with houses and shops built from local stone, with narrow lanes and alleys branching off it.

[11] In common with most of the Orkney isles, Mainland rests almost entirely on a bedrock of Old Red Sandstone, which is about 400 million years old and was laid down in the Devonian period.

The freshwater Lake Orcadie existed on the edges of these eroding mountains, stretching from Shetland to the southern Moray Firth.

[19] Many indications of glacial action exist in the form of striated surfaces in Kirkwall Bay, with boulder clay with marine shells, and many boulders of rocks foreign to the islands made of chalk, oolitic limestone, flint, &c. Local moraines are found in some of the valleys.

Most of the best known Neoloithic ancient monuments are located in west Mainland, which includes the "Heart of Neolithic Orkney", a UNESCO World Heritage Site.

The group constitutes a major prehistoric cultural landscape which gives a graphic depiction of life in the north of Scotland some 5,000 years ago.

Viking settlers comprehensively occupied Orkney, and Mainland became a possession of Norway until being given to Scotland during the 15th century as part of a dowry settlement.

Stromness became important during the late 17th century, when England was at war with France and shipping was forced to avoid the English Channel.

Work began in May 1940 and the barriers were completed in September 1944, but were not officially opened until 12 May 1945, four days after the end of World War II in Europe.

Fogs occur during summer and early autumn, and furious gales may be expected four or five times in the year.

[21][22] The Orkney-Caithness route would be connected to Mainland, via the Churchill Barriers, but would make landfall on South Ronaldsay, if constructed.

Loganair provides services to the Scottish Mainland (Aberdeen, Edinburgh, Glasgow and Inverness), as well as to Sumburgh Airport in Shetland.

[4] Some 4,000 ha of Mainland’s moorland has been designated an Important Bird Area (IBA) by BirdLife International because it supports populations of red-throated loons, short-eared owls, hen harriers and merlins.

Two rarities to be found here are the oyster plant (Mertensia maritima) and the Scottish primrose (Primula scotica).