The singer will join stars such as Sir Paul McCartney, Dame Shirley Bassey, Stevie Wonder, Kylie Minogue, Jessie J, Robbie Williams, Ed Sheeran and Cheryl Cole for the show on Monday (June 4).
John said: "It is the beginning of an incredible summer for Britain. It is an incredible honour to be asked to perform.
"I'm thrilled to have been asked and I'm really looking forward to it."
The concert, organised by Take That's Gary Barlow, will celebrate the Queen's 60-year reign. Members of the Royal Family, including Prince Philip, will be in attendance at the event, which will be staged in the surroundings of the Queen Victoria Memorial in front of Buckingham Palace.
An insider is quoted as tellng the Daily Star that they believe the show will be seen by billions of people.
"This is going to be one of the biggest concerts in the history of this island, with an audience from around the world," the source said.
"Gary Barlow has really surpassed himself in getting such quality acts all in one place for the greatest celebration Her Majesty has ever witnessed."
Watch Sir Elton John perform 'Hey Ahab' with Leon Russell live in New York below:
Photo gallery - Diamond Jubilee concert at Buckingham Palace: