Emma Watson, Dan Radcliffe, and Rupert Grint will be among the celebs taking part in a Royal birthday celebration for children. They will be peforming in a kids' play to mark the Queen of England's 80th birthday.
Two thousand children have been given tickets for the event.

The Queen had her real 80th birthday on 21 April, but she also gets an official birthday, on 17 June.

The play, called The Queen's Handbag, is part of the Children's Party at the Palace. It will be broadcast on BBC One and the CBBC Channel on the day.

The idea behind the party is to celebrate the success of British children's literature and to encourage kids to read more. The play's storyline is top secret, but organisers say there will be a specially-written scene including Harry and his friends.

Source: CBBC Newsround