After the Trooping the Colour the King's Troop Royal Horse Artillery fired a 41-gun salute in Green Park to mark the Queen's official birthday.
The royals then gathered on the balcony at Buckingham Palace to watch the traditional RAF flypast.
Thousands of spectators crowded around the front of the palace and on The Mall, many cheering as a succession of planes roared overhead.
The Duchess of Cambridge, who is eight months pregnant, was all smiles at the Trooping the Colour parade - her last public engagement before she gives birth in mid-July.
The Duchess of Cambridge has made an appearance at the Trooping the Colour parade, which will be her last public engagement before her baby is born in mid-July.
Wearing a pale pink Alexander McQueen coat and matching hat, Kate, who is eight months pregnant, travelled to the pageant in a carriage with the Duchess of Cornwall and Prince Harry.
The Queen will celebrate her official birthday today with the Trooping the Colour parade of more than 1,000 soldiers and horses.
The Queen will ride in a vintage carriage from Buckingham Palace along The Mall to Horse Guards Parade.
As the Duke of Edinburgh is still recovering in hospital from exploratory abdominal surgery, the monarch has invited her cousin, the Duke of Kent, to join her for the short journey.
The Duchess of Cambridge, attending her last public engagement before her baby is born in mid-July, will ride in a carriage with the Duchess of Cornwall and Prince Harry.
Prince Charles has led the Welsh Guards in the final rehearsal for this year’s Queen’s Birthday Parade.
The Colonel's Review is the final dress rehearsal before the Trooping the Colour, which will be held next Saturday in front of the Queen.
The Queen is currently spending the weekend in Windsor as the Duke of Edinburgh recovers in hospital following his exploratory operation. The Duke is expected to miss the event.