The actress left the legal drama when her relationship with Prince Harry started to get serious, but she still counts a number of the cast members as good friends.
And while the guestlist for the wedding, which will be attended by 600 people, has not been made public, some of the 'Suits' stars' social media updates appear to suggest that they'll be at the nuptials.
Gabriel Macht, who plays Harvey Specter, has gone slightly quiet on Twitter and Instagram lately, but his wife, Jacinda Barrett, has been posting pictures from Europe.
On Sunday (13 May), Jacinda - who also guest-starred in three episodes of 'Suits' back in 2012 - shared an adorable snap of herself and son Luca outside Buckingham Palace.
Two days earlier, she shared her packing woes on Instagram, captioning a picture of herself in a long, pink dress with: "Getting ready to fly to Europe, got places to go and people to see, but still deciding what to wear. Getting a little love from @emiliawickstead on this one."
Could this be a hint at what she'll wear on Saturday? Watch this space.
Sarah Rafferty, who stars as Donna Paulsen, is also in Europe, and is currently spending some time in Paris.
Sharing a photo of one of her daughters outside the Louvre, she wrote: "Dear Paris, I'm pleased to introduce you to my littlest one. She likes sweets. I'm confident you'll show her a good time."
One 'Suits' star who has revealed nothing online is Patrick J Adams, who played Meghan's on-screen husband, Mike Ross.
Back when the engagement was first announced, Patrick jokingly tweeted about the news before sharing heartfelt congratulations.
"Playing Meghan's television partner for the better part of a decade uniquely qualifies me to say this: Your Royal Highness, you are a lucky man and I know your long life together will be joyful, productive and hilarious. Meghan, so happy for you, friend. Much love," he wrote.
The actor later joked about trying to pick a wedding gift for the pair. "We were trying to choose between like a blender or bread maker. You know something classy, like a good blender," he told Entertainment Tonight. "Like a Vitamix, yeah. She's gonna need a Vitamix for sure."
According to various US publications, other 'Suits' stars expected to attend include Gina Torres. Bonnie Hammer, an executive at NBCUniversal, is also reportedly set to be there.