Kylesku is a small, remote fishing hamlet in Sutherland in the Scottish Highlands. Until 1984, it was the site of a free ferry.

Kylesku is located where Loch Glencoul and Loch Gleann Dubh join to form a sea passage Loch a' Chàirn Bhàin which links to Eddrachillis Bay. It is in the Scottish council area of Highland.

The village stretches back along the road from the slipway that used to be the southern end of the ferry crossing. Now by-passed by the main road carried over the bridge, the Kylesku Hotel overlooks the slipway. Nearby is Eas a' Chual Aluinn, Britain's highest waterfall. This can be visited on a boat trip aboard Rachael Clare.

Kylesku sits at the centre of an area which has become Scotland's first 'Global Geopark'. There is abundant wildlife and a wide range of outdoor pursuits in or on the lochs, mountains and white sandy beaches, including bird watching, seal and otter spotting, fishing, climbing and hill walking.

There was a passenger ferry (a rowing boat) in the early 19th century. Commercial traffic mainly comprised cattle on their way to central Scotland, and they had to swim across. Over the years, various ferries came and went, and small car-carrying ferries first appeared between the wars. The Kylesku Ferry was unusual in being free for much of its life.

The Maid of Kylesku, a two car ferry, was built for the Kylesku crossing in the early 1950s, where it was operated until replaced by the Queen of Kylesku in 1967. When no longer needed, the Maid of Kylesku was beached on the opposite side of the bay.

In 1976, the Maid of Glencoul, built in Ardrossan, became the first vessel capable of carrying fully loaded commercial vehicles. After the opening of the Kylesku Bridge, it was used as the Corran Ferry.

The ferry service became known as a dreaded bottleneck on the route and was replaced by the Kylesku Bridge in 1984. Opened by the Queen, the bridge is 276 metres (906 ft) long and crosses a 130-metre (430 ft) stretch of water. The curving, five-span, continuous, pre-stressed concrete, hollow bridge has been described as one of the most beautiful bridges in the world.[ The bridge was built by Morrison Construction Group and designed by the architects Arup (intended to complement the natural beauty of the site), and it has won several design and construction awards.

A cairn on the north side, erected in 1993, commemorates the 50th anniversary of the formation of the XIIth Submarine Flotilla, a unit of "X-craft" and "Chariot" miniature submarines, which trained in Lochs Glendhu and Glencoul from 1943.

Assynt (a short distance to the north) is a sparsely populated area and is known for its landscape and its remarkable mountains, which have led to the area, along with neighbouring Coigach, being designated as the Assynt-Coigach National Scenic Area, one of 40 such areas in Scotland.

The western part of Assynt has many distinctively shaped mountains, including Quinag, Canisp, Suilven and Ben More Assynt, that rise steeply from the surrounding "cnoc and lochan" scenery. These can often appear higher than their actual height would indicate due to their steep sides and the contrast with the moorland from which they rise. Many of the most distinctive peaks such as Suilven were formed during the last Ice Age, when they were left exposed above the ice sheet as nunataks, and they now remain as inselbergs of highly eroded Torridonian sandstone sitting on a bedrock of much older Lewisian gneiss. The Moine Thrust runs through the area, and is most visible at Knockan Crag National Nature Reserve, which includes a visitor centre interpreting the geological features of the landscape. In the east of Assynt lies a region of limestone scenery surrounding Ben More Assynt. This part of Assynt hosts the longest cave in Scotland, Uamh an Claonaite, which lies five miles (eight kilometres) south of Inchnadamph. The geological importance of Assynt is reflected in its inclusion in the North West Highlands Geopark.

The name Assynt may derive from an Old Norse word meaning 'ridge end'. There is also a tradition that the name comes from a fight between the two brothers Unt and Ass-Unt, (meaning Man of Peace and Man of Discord). The latter having won the tussle gave his name to the parish.