Mac Bethad mac Findlaích (MacBheatha mac Fhionnlaigh), anglicised as Macbeth, and nicknamed Rí Deircc, "the Red King"; died 15 August 1057) was King of the Scots (also known as the King of Alba, and earlier as King of Moray and King of Fortriu) from 1040 until his death. He is best known as the subject of William Shakespeare's tragedy Macbeth and the many works it has inspired, although the play presents a highly inaccurate picture of his reign and personality.

Macbeth did not survive the English invasion, for he was defeated and mortally wounded or killed by the future Malcolm III ("King Malcolm Ceann-mor", son of Duncan I) on the north side of the Mounth in 1057, after retreating with his men over the Cairnamounth Pass to take his last stand at the battle at Lumphanan.

The Prophecy of Berchán has it that he was wounded and died at Scone, sixty miles to the south, some days later.Macbeth's stepson Lulach mac Gille Coemgáin was installed as king soon after.