Prince Harry and Meghan Markle's wedding: Which celebrities could be invited?

Following the announcement that Prince Harry and Meghan Markle are engaged, speculation around their upcoming nuptials has kicked into high gear.

On Tuesday morning, one day after the engagement reveal, it was announced that their wedding would take place in May of 2018 on the grounds of one of Queen Elizabeth's castles. St. George's Chapel is located at Windsor Castle, where the Queen lives for part of the year. Her Majesty has given permission for the wedding to take place there.

SEE ALSO: Prince Harry says Meghan Markle and Princess Diana 'would have probably been best friends'

But one of the many remaining mysteries about the next royal weddings is who will snag invites.

See photos from Meghan Markle and Prince Harry's engagement photo call:

27 PHOTOS
Prince Harry and Meghan Markle engagement photo call
See Gallery
Prince Harry and Meghan Markle engagement photo call
Britain's Prince Harry and his fianc� US actress Meghan Markle pose for a photograph in the Sunken Garden at Kensington Palace in west London on November 27, 2017, following the announcement of their engagement. Britain's Prince Harry will marry his US actress girlfriend Meghan Markle early next year after the couple became engaged earlier this month, Clarence House announced on Monday. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Britain's Prince Harry and his fianc� US actress Meghan Markle pose for a photograph in the Sunken Garden at Kensington Palace in west London on November 27, 2017, following the announcement of their engagement. Britain's Prince Harry will marry his US actress girlfriend Meghan Markle early next year after the couple became engaged earlier this month, Clarence House announced on Monday. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
LONDON, ENGLAND - NOVEMBER 27: Meghan Markle with her engagemnt ring during an official photocall to announce the engagement of Prince Harry and actress Meghan Markle at The Sunken Gardens at Kensington Palace on November 27, 2017 in London, England. Prince Harry and Meghan Markle have been a couple officially since November 2016 and are due to marry in Spring 2018. (Photo by Mark Cuthbert/UK Press via Getty Images)
LONDON, ENGLAND - NOVEMBER 27: Prince Harry and actress Meghan Markle during an official photocall to announce their engagement at The Sunken Gardens at Kensington Palace on November 27, 2017 in London, England. Prince Harry and Meghan Markle have been a couple officially since November 2016 and are due to marry in Spring 2018. (Photo by Chris Jackson/Chris Jackson/Getty Images)
LONDON, ENGLAND - NOVEMBER 27: Prince Harry and Meghan Markle during an official photocall to announce the engagement of Prince Harry and actress Meghan Markle at The Sunken Gardens at Kensington Palace on November 27, 2017 in London, England. Prince Harry and Meghan Markle have been a couple officially since November 2016 and are due to marry in Spring 2018. (Photo by Mark Cuthbert/UK Press via Getty Images)
LONDON, ENGLAND - NOVEMBER 27: Prince Harry and actress Meghan Markle during an official photocall to announce their engagement at The Sunken Gardens at Kensington Palace on November 27, 2017 in London, England. Prince Harry and Meghan Markle have been a couple officially since November 2016 and are due to marry in Spring 2018. (Photo by Chris Jackson/Chris Jackson/Getty Images)
Britain's Prince Harry stands with his fianc� US actress Meghan Markle as she shows off her engagement ring whilst they pose for a photograph in the Sunken Garden at Kensington Palace in west London on November 27, 2017, following the announcement of their engagement. Britain's Prince Harry will marry his US actress girlfriend Meghan Markle early next year after the couple became engaged earlier this month, Clarence House announced on Monday. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Britain's Prince Harry and his fianc� US actress Meghan Markle pose for a photograph in the Sunken Garden at Kensington Palace in west London on November 27, 2017, following the announcement of their engagement. Britain's Prince Harry will marry his US actress girlfriend Meghan Markle early next year after the couple became engaged earlier this month, Clarence House announced on Monday. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Prince Harry and Meghan Markle at a photocall to announce their engagement at Kensington Palace, London. Photo credit should read: Doug Peters/EMPICS Entertainment
Prince Harry and Meghan Markle at a photocall to announce their engagement at Kensington Palace, London. Photo credit should read: Doug Peters/EMPICS Entertainment
Prince Harry and Meghan Markle at a photocall to announce their engagement at Kensington Palace, London. Photo credit should read: Doug Peters/EMPICS Entertainment
Prince Harry and Meghan Markle at a photocall to announce their engagement at Kensington Palace, London. Photo credit should read: Doug Peters/EMPICS Entertainment
Britain's Prince Harry and his fianc� US actress Meghan Markle pose for a photograph in the Sunken Garden at Kensington Palace in west London on November 27, 2017, following the announcement of their engagement. Britain's Prince Harry will marry his US actress girlfriend Meghan Markle early next year after the couple became engaged earlier this month, Clarence House announced on Monday. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
US actress Meghan Markle shows reacts as she poses with her fianc� Britain's Prince Harry in the Sunken Garden at Kensington Palace in west London on November 27, 2017, following the announcement of their engagement. Britain's Prince Harry will marry his US actress girlfriend Meghan Markle early next year after the couple became engaged earlier this month, Clarence House announced on Monday. / AFP PHOTO / DANIEL LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Britain's Prince Harry and his fianc� US actress Meghan Markle pose for a photograph in the Sunken Garden at Kensington Palace in west London on November 27, 2017, following the announcement of their engagement. Britain's Prince Harry will marry his US actress girlfriend Meghan Markle early next year after the couple became engaged earlier this month, Clarence House announced on Monday. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Britain's Prince Harry and his fianc� US actress Meghan Markle arrive to pose for photographs in the Sunken Garden at Kensington Palace in west London on November 27, 2017, following the announcement of their engagement. Britain's Prince Harry will marry his US actress girlfriend Meghan Markle early next year after the couple became engaged earlier this month, Clarence House announced on Monday. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
LONDON, ENGLAND - NOVEMBER 27: Prince Harry and actress Meghan Markle during an official photocall to announce their engagement at The Sunken Gardens at Kensington Palace on November 27, 2017 in London, England. Prince Harry and Meghan Markle have been a couple officially since November 2016 and are due to marry in Spring 2018. (Photo by Chris Jackson/Chris Jackson/Getty Images)
LONDON, ENGLAND - NOVEMBER 27: Prince Harry and actress Meghan Markle during an official photocall to announce their engagement at The Sunken Gardens at Kensington Palace on November 27, 2017 in London, England. Prince Harry and Meghan Markle have been a couple officially since November 2016 and are due to marry in Spring 2018. (Photo by Chris Jackson/Chris Jackson/Getty Images)
Britain's Prince Harry and his fianc� US actress Meghan Markle pose for a photograph in the Sunken Garden at Kensington Palace in west London on November 27, 2017, following the announcement of their engagement. Britain's Prince Harry will marry his US actress girlfriend Meghan Markle early next year after the couple became engaged earlier this month, Clarence House announced on Monday. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
LONDON, ENGLAND - NOVEMBER 27: Prince Harry and actress Meghan Markle during an official photocall to announce their engagement at The Sunken Gardens at Kensington Palace on November 27, 2017 in London, England. Prince Harry and Meghan Markle have been a couple officially since November 2016 and are due to marry in Spring 2018. (Photo by Chris Jackson/Chris Jackson/Getty Images)
Britain's Prince Harry and his fianc� US actress Meghan Markle pose for a photograph in the Sunken Garden at Kensington Palace in west London on November 27, 2017, following the announcement of their engagement. Britain's Prince Harry will marry his US actress girlfriend Meghan Markle early next year after the couple became engaged earlier this month, Clarence House announced on Monday. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Britain's Prince Harry stands with his fianc� US actress Meghan Markle as she shows off her engagement ring whilst they pose for a photograph in the Sunken Garden at Kensington Palace in west London on November 27, 2017, following the announcement of their engagement. Britain's Prince Harry will marry his US actress girlfriend Meghan Markle early next year after the couple became engaged earlier this month, Clarence House announced on Monday. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
Prince Harry and Meghan Markle in the Sunken Garden at Kensington Palace, London, after the announcement of their engagement. (Photo by Dominic Lipinski/PA Images via Getty Images)
LONDON, ENGLAND - NOVEMBER 27: Prince Harry and Meghan Markle during an official photocall to announce the engagement of Prince Harry and actress Meghan Markle at The Sunken Gardens at Kensington Palace on November 27, 2017 in London, England. Prince Harry and Meghan Markle have been a couple officially since November 2016 and are due to marry in Spring 2018. (Photo by Mark Cuthbert/UK Press via Getty Images)
LONDON, ENGLAND - NOVEMBER 27: Prince Harry and Meghan Markle during an official photocall to announce the engagement of Prince Harry and actress Meghan Markle at The Sunken Gardens at Kensington Palace on November 27, 2017 in London, England. Prince Harry and Meghan Markle have been a couple officially since November 2016 and are due to marry in Spring 2018. (Photo by Mark Cuthbert/UK Press via Getty Images)
Britain's Prince Harry and his fianc� US actress Meghan Markle pose for a photograph in the Sunken Garden at Kensington Palace in west London on November 27, 2017, following the announcement of their engagement. Britain's Prince Harry will marry his US actress girlfriend Meghan Markle early next year after the couple became engaged earlier this month, Clarence House announced on Monday. / AFP PHOTO / Daniel LEAL-OLIVAS (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)
HIDE CAPTION
SHOW CAPTION
of
SEE ALL
BACK TO SLIDE

Being an actress on the USA Network's long-running hit drama series, "Suits," Markle is surely expected to invite some of her co-stars from the show. She's particularly close to Patrick J. Adams, who plays her love interest on the show, so he will almost certainly be invited -- but will he bring wife Troian Bellisario from "Pretty Little Liars" as his date?

Other possible celebrity invitees include Markle's close pals Priyanka Chopra and Serena Williams, who the actress once referred to as her "confidant." The two stars have been friends for years, though Markle notably didn't attend the tennis legend's wedding earlier this month.

From Harry's side, there's speculation that David and Victoria Beckham are likely to receive invitations to the wedding, too. Former US President Barack Obama is also a friend of Harry's, and the two seemed to grow close after their collaboration on the Invictus Games. 

RELATED: See photos from Serena Williams' star-studded wedding:

21 PHOTOS
Inside Serena Williams' wedding
See Gallery
Inside Serena Williams' wedding
For the first dress When Anna Wintour asked me what I wanted to wear I said "a cape" I just want to wear a cape" she said: "well Sarah Burton with @alexandermcqueen is the one for you.” Thanks Anna. Thanks Sarah. I felt like a princess and superwoman all at once. 📸: @mistadubb @ericamelissa_
After tying the knot with @alexisohanian last night, @serenawilliams debuted her second dress of the evening, a dramatic beaded, feathered @versace_official moment that made her look like a fashion-forward superwoman. Tap the link our bio to see all the stunning photos. Photographed by @melbarlowandco and @allanzepedaphotography.
Official. 📸 @melbarlowandco @allanzepedaphotography
@serenawilliams married @alexisohanian in a stunning Sarah Burton for @alexandermcqueen princess gown. Tap the link in our bio for more exclusive photos from the star-studded celebration. Photographed by @mistadubb and @ericamelissa_.
I love you both and I'm so incredibly proud of you! Welcome to the club! ❤😍❤😍❤😍❤😍❤😍❤
“You are the greatest of all time, not just in sport. I’m talking about as a mother, and as a wife. I am so excited to write so many more chapters of our fairy tale together.” Congratulations to @serenawilliams and @alexisohanian, who exchanged vows last night. Tap the link in our bio to see the exclusive first photos from their fairytale wedding in New Orleans. Photographed by @melbarlowandco and @allanzepedaphotography.
💃🏿🕺🏻 📸 @melbarlowandco @allanzepedaphotography
Dance with new edition? Check ✅. 📸: Bob Metelus and Erica Rodriguez
Squad....💙💛celebrating love❤️
@serenawilliams: You are the greatest of all time, not just in sport--I’m talking about as a mother and as a wife. I am so excited to write so many more chapters of our fairy tale together. And my whole life I didn’t even realize it, but I was waiting for this moment. And everything that I have done, everything that I am so proud of in my career, and in my life, for the last 34 years, pales in comparison to what we’re doing today. And I am so grateful, and I am so in love. 📸 @melbarlowandco @allanzepedaphotography
Alani & Kimmie❤️THE ROYAL BALL 👑🎩
Each one of my groomsmen is a best friend who also represents a different period of my life. Jon: childhood Huu: @uva Steve: @reddit Michael: my book & tour, Without Their Permission Garry: Initialized Capital To be rich with great friends is a privilege -- and it's no surprise that they all love my bride.
Dressed for The Most Royal Ball 🌹
The Royal Ball. @MichaelCostello ❤️
THE ROYAL BALL 👑🎩 @verawanggang
Yaaaaaay!! So Happy! God is so Good! Love you @AlexisOhanian & @SerenaWilliams! Yallz Murrrred! 🙌🏽🥂💍❤️
Now i can say that i was at one of the most beautiful weddings ! That room was so filled with joy and love . Real Love with real folks. Congratulations to this amazing couple. Alex and Serena ❤️
Meet Michelle @merakimishell the amazing woman behind my incredible @nike Cortez shoes? Yes I wore them down the asile! Comfort for this bride! Thanks Michelle!!! 😍😍
HIDE CAPTION
SHOW CAPTION
of
SEE ALL
BACK TO SLIDE

More from AOL.com:
Camilla, Duchess of Cornwall reacts to Prince Harry and Meghan Markle's engagement
Twitter users are convinced that Carson Wentz and Prince Harry are the same person
Meghan Markle clears up 'misconception' about herself following engagement to Prince Harry

Read Full Story

Sign up for Entertainment Insider by AOL to get the hottest pop culture news delivered straight to your inbox!

Subscribe to our other newsletters

Emails may offer personalized content or ads. Learn more. You may unsubscribe any time.