A deserted spot on the border between Scotland and England.
The scene opens with a chorus of refugees who have fled from persecution by Macbeth in Scotland («Patria oppressa!»). Malcolm has put his trust in England’s help, but has gathered an army to invade Scotland. Macduff too, after the murder of his family, has joined the invaders. Malcolm exhorts them
all to hide their presence from the enemy by advancing under the cover of branches cut from the nearby Birnam Wood.

A room in Macbeth’s castle.
“Gran Scena del Sonnambulismo.” A prey to nightmares and madness, Lady Macbeth relives in a dream the murder of king Duncan, while confessing the crimes she has perpetrated.

A room in the castle.
Informed of his wife’s death, Macbeth prepares to face the enemy army. When it is announced that “Birnam Wood moves”, the king realises that the witches’ prophecy is coming true.

A plain surrounded by highlands and woods.
The battlefield. Malcolm’s army throw down the branches cut from Birnam Wood and attack Macbeth’s men, forcing them to retreat. The king is confronted by Macduff who, before drawing his sword, reveals that he was not born of woman but was “from his mother’s womb untimely ripped”. Macduff kills Macbeth and the victorious army acclaims Malcolm king of Scotland.