Loch Shin (Scottish Gaelic: Loch Sėn) is a loch in the Scottish North West Highlands. To the south is the small town of Lairg. The loch is the largest in Sutherland, runs from the north-west to the south-east and is 17 miles (27.2 kilometre) long.

In the 1950s, the level of the loch was raised by over 30 feet (10 metres) by the construction of Lairg Dam by Wimpey Construction as part of a hydro-electric scheme.

Around the loch are some mountain ranges; the 3273 foot (998 metre) Ben More Assynt in the west and Ben Klibreck (3154 feet/962 metre) to the east. The loch drains to the North Sea by way of the short River Shin that feeds into the Dornoch Firth.

Three miles to the north of Lairg is a monument to remember an early attempt to tame the Highlands. During the 1870s, the Duke of Sutherland ploughed up about 2,000 acres (8 km˛), but the industry never rewarded that. Today the area around the loch is one of the major farming centres for sheep in Scotland