She completed the elegant look with a neat bun, black clutch bag and simple pearl studs.
However, the olive colour scheme and designer - reported as Ralph Lauren by fashion-tracking site Meghan's Mirror - are new for her since she became a royal.
While traditionally Prince Louis' christening would have seen the 11-week old as the centre of attention, this wasn't entirely the case.
Russian Federation celebrates team's run despite World Cup exit
The video of her celebration in the VIP box in front of a visibly sad Russian PM has gone viral over social media. Stick to what you're doing, I'm behind you", he added.
Britain's Queen Elizabeth arrives at Westminster Abbey for a service to mark the centenary of the Royal Air Force (RAF), in central London, Britain July 10, 2018.
"It's clearly a style that she feels comfortable with, which is so important when you're stepping out in front of the cameras."
Check out some of the photos of the stunning Meghan Markle and her fellow royals at Westminster.
During the event, one hundred RAF aircraft will fly across England to celebrate the Royal Air Force's 100th anniversary.
How to download iOS 11.4.1 to your iPhone and iPad
Importantly, this technique would only work if the iOS device is not already in USB Restricted Mode when captured. In order to let the accessory connect, you have to unlock the iPhone with a passcode, Touch ID, or Face ID.
The Duchess of Cambridge is clad in an icy blue Alexander McQueen dress with three-quarter length sleeves and her signature neckline, which she's paired with a matching hat by Sean Barrett and nude heels.
As well as being Britain's top defense system in air, the RAF has prevented conflicts and delivered aid in areas hit by natural disasters over the last many decades.
The British royal family have had a very busy Summer already, and are showing no sign of slowing down.
The service will be followed by a fly-by at Buckingham Palace and another balcony appearance from the royal family.
Hamilton questions Ferrari 'tactics' after first-lap spin
Hamilton said that his immediate post-race remarks were down to the exhaustion he felt after such a demanding race. Red Bull will switch to Honda power next year, and the move seemingly can not come soon enough for Max Verstappen.
Meghan Markle seems to be in an experimental mood as she can be seen trying new sophisticated attires.