It is not known who kills Banquo but it is Macbeth who orders for him to be murdered.
Macbeth sees the ghost of the recently murdered Banquo.
Banquo is a character in William Shakespeare's play "Macbeth" who is a loyal and honorable general. He is a friend of Macbeth and his descendants are said to be the future kings of Scotland according to the witches' prophecy. Banquo is murdered by Macbeth in his quest for power.
When Macbeth mentions Banquo's absence, he reflects on the fact that Banquo is not present for a royal banquet. This moment triggers Macbeth's guilt and anxiety about Banquo's prophecy that his descendants will inherit the throne, leading to his decision to have Banquo and his son murdered.
The boy murdered by Macbeth's assassins was Young Siward, the son of Siward, Earl of Northumberland. He was killed during the battle between Macbeth's forces and Siward's army.
In Shakespeare's play "Macbeth," the ghost that haunts Macbeth is the ghost of Banquo, a former friend whom Macbeth has murdered in order to secure his position as king. The ghost appears during a banquet hosted by Macbeth and is only visible to him, causing Macbeth to react with guilt and terror.
Banquo doesn't commit any crime but is murdered at Macbeth's command. -APEX
*Banquo. Macbeth's best friend is Banquo, but he is also Macbeth's enemy. After the meeting with the witches, Macbeth finds out that he will become the Thane of Cawdor and the King of Scotland. Eventually, he achieves both of these prophecies. Banquo, Macbeth, and Lady Macbeth are the only people that know about the witches. Banquo becomes suspicious of Macbeth because Macbeth fulfills the prophecy after King Duncan is murdered, and Macbeth acknowledges this fact. Basically, Macbeth doesn't trust Banquo.
In Act Three of The Tragedy of Macbeth, Macbeth hires murderers to kill Banquo and his son, Fleance. The murderers successfully kill Banquo, but Fleance manages to escape, leaving Macbeth's desire to secure the throne unfulfilled.
Macbeth says that he wishes Banquo was present at the dinner, yet Macbeth murdered Banquo. Macbeth proposed a toast to Banquo so that the Lords would not suspect Macbeth of any foul play. However, later on in this scene Macbeth betrayed himself. He thought he could see Banquos ghost, and he was acting strangely. The Lords were very confused and thought he was going mad and Lady Macbeth had to act for Macbeth and try and save their reputation.
Macbeth sees the ghost of the recently murdered Banquo.
Macbeth kills Banquo in the play and then Banquo's ghost haunts Macbeth.