Up to 100 aircraft will fly above the county on their way to a flypast over Buckingham Palace to celebrate the RAF's 100th birthday.
They include Meghan's hairdresser George Northwood, who did her relaxed updo at the couple's evening wedding reception.
(Picture: Getty) Heir to the throne Prince Charles and his wife Camilla, his son Prince William and wife Kate, and Prince Harry and his wife Meghan, all joined the queen on the palace balcony for the display.
The couple met RAF servicemen and women, charity representatives involved in the RAF100 Appeal, RAF Veterans and Civil Service personnel involved in the Centenary celebrations.
Meghan debuted her third outfit of the day, wearing a stunning belted black cocktail dress by designer Emilia Wickstead.
They will meet Irish President Michael D. Higgins before visiting an Irish emigration museum, a technology startup hub and Trinity College, Ireland's oldest university.
Scores of jets, aeroplanes and helicopters were taking part in the "once-in-a-lifetime" event, spanning the history of the RAF.
One day you're shaking hands with the Archbishop of Canterbury at Prince Louis's christening, the next you're staring up at the sky to watch a military flyover at Buckingham Palace.
The anniversary brought the royal fab four together again.
This year marks the centenary of the Royal Air Force - the world's first independent air force - which was founded on 1 April 1918, independent of the British Army and Royal Navy.
A century later, the RAF is engaged in 13 missions across 26 countries and is heavily committed on operations both at home and overseas, according to Buckingham Palace.