The Mackays of Aberach also known as the Clan Aberach are a Scottish family and a branch of the ancient Clan Mackay of the Scottish Highlands. They were the senior cadet branch of the Clan Mackay and were seated at Achness, in Strathnaver, which is in modern-day Sutherland. In Scottish Gaelic they are known as the Sleaght-ean Aberigh (descendants of John Aberach).