The couple were at an event that aims to inspire the next generation of young women to pursue careers in Science, Technology, Engineering and Maths.
Meghan wore a navy J Crew coat with thick white piping, which she tied at waist to add some shape.
She paired it with a white polo neck jumper from All Saints and plain black three-quarter length Alexander Wang trousers.
Prince Harry’s fiancee completed the look with a smal navy handbag and black suede court shoes.
But the look broke what is considered a key style rule – that blue and black should never be worn together.
Meghan stylish outfit made a strong case for breaking the fashion edict.
The former Suits actress wore her hair, which was looking very long, curled over her shoulders.
Keeping her makeup simple, Meghan wore smoky etes and a nude lip. Her nails were also bare – as is the custom for royal women.
Meghan has been following royal style rules relatively closely since her engagement to Prince Harry.
One thing she has picked up in particular is “the Duchess slant“. This is a seating position named after Kate Middleton, but it has been in the Royal Family for much longer and has been used by the Queen and Princess Diana.
Royals never cross their legs at the knee, as it is deemed unladylike, and risks others getting a view up your skirt.
It is key to keep your knees and ankles tucked closely together.
Myka Meier, royal etiquette expert and founder and director of Beaumont Etiquette, told People: “Typically the ‘duchess slant’ is used when a lady has to sit for an extended amount of time while keeping poise and posture.
“It is the perfect pose for when a camera is shooting directly in front of you because by slightly slanting the knees to create a zig-zag effect when wearing a dress or skirt, your legs are angled so that the camera only shoots the sides of your legs and protects your modesty.”
It has been a busy week for Meghan, who it was reported underwent a secret baptism earlier this week in preparation for her wedding in May.