The Prince of Wales and the Duke of Cambridge will open Parliament, after the Queen granted special permission.
It will be Prince William’s first state opening, and he and Prince Charles will be accompanied by the Duchess of Cornwall.
It is the first time since 1963 that the Queen will not deliver the speech.
At that time, she was pregnant with Prince Edward, and it was instead read by the Lord Chancellor.
The Queen’s main throne will remain empty in the House of Lords on Tuesday.
The decision for Prince Charles to take the Queen’s place was taken on Monday and a new Letters Patent authorised by the monarch was issued to delegate the opening of Parliament to the Counsellors of State.
This is the category of royal that includes the next four people in the line of succession who are over the age of 21.
Buckingham Palace said on Monday that the decision to pull out had been taken in consultation with the Queen’s doctors, as she continues to experience “episodic mobility problems”.
The Palace said in a statement: “At Her Majesty’s request, and with the agreement of the relevant authorities, The Prince of Wales will read The Queen’s Speech on Her Majesty’s behalf, with The Duke of Cambridge also in attendance.”