The ceremony marked Queen Elizabeth's 92nd birthday.
Trooping the Colour and the day in Cheshire represent the beginning of the busy royal summer season.
Prince Harry kept Meghan clued in about how the event works.
Case in point: Meghan Markle and Prince Harry's first appearance at Trooping the Colour as a married couple.
The former-actress opted for a dress by renowned designer, known for her impeccable sense of personal style.
Meghan Duchess of Sussex attends Trooping The Colour.
Aide Who Made Comment About McCain ‘Dying’ Out at WH
Sadler was responsible for compiling and distributing talking points to allies of the Trump administration. John McCain (R-AZ) being irrelevant because she predicted he would soon succumb to brain cancer.
The Duke and Duchess of Sussex have taken their places for the first time with the Queen on Buckingham Palace's balcony after Trooping the Colour.
The two young Royals grinned in excitement as they watched a series of fighter jets and planes fly overhead.
"When you get into it I'll tell you more later", he apparently said, before adding, "Then there's the flypast and then we all look up to the sky".
Kate - in a $68 Zara sundress and summer wedges - sat on the ground to watch her husband play, plonked Charlotte on her lap and broke into a run down a small hill. Kate picked her up immediately and comforted her.
Princess Diana also never wore a short-sleeved look to the official celebration of the Queen's birthday from her first appearance in 1981.
When totalling up the cost of Meghan's garments, the outfit in total costs nearly £11,000 at £10,817.26 - a price tag fit for a duchess. However, the Mayo News confirmed the Royals were not staying at the famous Ashford Castle in County Mayo since it was booked for a corporate event, reports RTE.
Savannah Phillips, the Queen's great-granddaughter, appeared unimpressed with Prince George's endless chatter and slapped a hand over his mouth to keep him quiet. "She really wants his views", the source said.