The Queen and the Duke of Edinburgh will open the London 2012 Paralympic Games in the Olympic Stadium on Wednesday 29 August.
This will be the first time The Queen has opened a Paralympic Games.
She will also open the Olympic Games on Friday 27 July.
In 1976 the Queen opened the Montreal Olympic Games and in 1956 The Duke of Edinburgh (on behalf of The Queen) opened the Melbourne Olympic Games.
And the 1984 Paralympic Games were officially opened by The Prince of Wales.
Chairman of the organising committee for the Olympic and Paralympic Games Sebastian Coe said: “This Paralympic Games will be the largest ever and the Opening Ceremony on 29 August will be a fantastic event.
“The Paralympic Games will undoubtedly be a time of extraordinary pride for our nation, and it is fitting that Her Majesty will declare us underway.”