Loch Ewe (Scottish Gaelic: Loch Iùbh) is a sea loch in the region of Wester Ross in the Northwest Highlands of Scotland. The shores are inhabited by a traditionally Gàidhlig-speaking people living in or sustained by crofting villages, the most notable of which, situated on the north-eastern shore, is the Aultbea settlement.

Due to the rugged and inaccessible terrain in which it is located, Loch Ewe has always been an assembly point for maritime trade. Around 1610 the area at the head of Loch Ewe, today known as Poolewe, was urbanised around an iron furnace using charcoal produced in the surrounding woodlands for fuel. English ironmasters found it more economic to ship the ore to Poolewe for smelting than to ship the processed charcoal to England to run furnaces there.

The crofting villages which were established in the 1840s, as a result of the local parish's estate being reformed from run-rig to fixed holdings properties, were always quite small. Bualnaliub, nine miles (fifteen kilometres) to the north of Poolewe, had eleven houses and fifty people at the 1841 census – twenty-three of whom were from the same (McIver) family. Mellon Charles, four miles (six kilometres) to the west, had two hundred and sixteen people in forty-one houses – including seventeen houses headed by a McLennan. Ormiscaig, roughly halfway between them, had ten houses (four headed by McGregors) totalling forty-eight people. One hundred and forty years later, in 1981, the population was ten at Bualnaluib, twenty-four at Ormiscaig and one hundred and ten at Mellon Charles.

In 1911 a 70-foot (21-metre) lighthouse was built on the promontory between Gairloch and Poolewe.

Loch Ewe was a temporary base of the Home Fleet during the Second World War. It was also used as an assembly point for the Arctic Convoys during the war. Ships from the British, American and other ports gathered here before sailing to Murmansk from September 1942 following the disaster of Convoy PQ 17 in order to confuse German intelligence.

At the German surrender in April 1945 Loch Ewe became the British marshalling point for many of the German U-boats that had surrendered while at sea.

According to the published correspondence of a local resident, the Royal Navy established watchkeeping defences around an inlet to the south-east of Loch Ewe, sourcing the area for its cod, haddock, and mackerel reserves:

Our farmhouse was used as a barracks by the anti-aircraft battery which had emplacements around the south and east sides of the Loch [Ewe]. The concrete foundations and bomb shelters [built out of favour for the locals] still remain in the Torridon Hills. The gunners lived in a large wooden hut on the bank above the house. There was an enormous balloon shed by the shore for barrage balloons. We kept the sea boats there in winter, when the gales were prodigious. On the shore was a small concrete jetty, off which lay a summer mooring for the lobster boat. The navy had very kindly put in this mooring for my parents – a buoy about three feet [90 cm] long, with a chain down to a large concrete block on the seabed.