Before this change in roles she was a successful TV actress with a role in legal drama Suits.
Kate Middleton, on the other hand, met her husband Prince William, 36, at St Andrew’s University, where she studied art history.
Express.co.uk looked at how each woman dresses for charity galas.
Meghan Markle has opted for a workwear inspired look since she became the Duchess of Sussex.
The former-actress portrayed a paralegal and worked in the American Embassy in Buenos Aires, so it is likely the former career girl feels at home in tailoring.
She wore a tuxedo dress with black heels to a performance of Hamilton at the Victoria Palace Theatre on 29 August.
Then to the WellChild awards at the Royal Lancaster Hotel on 4 September she wore a tuxedo suit with wide legs.
Her hair was scraped back in a bun on both occasions.
Meghan has previously said that she has been inspired by her Suits character in terms of her style.
Jolie Andreatta, the Suits costume designer, told Harper’s Bazaar: “Meghan and I loved Rachel’s clothes. We’d always say that, if we could, we would live in Rachel’s clothes.
“Designing Rachel’s look was like being a kid in a candy store.”
Kate Middleton’s approach to charity galas has been more inspired by evening wear.
The stunning Duchess of Cambridge, who is also a mother-of-one, appears to like her long hemlines and ultra-feminine silhouettes.
The future Queen attended the 2017 Gala Dinner for The Anna Freud National Centre for Children and Families wearing a floor length black gown with lace sleeves.
She added a black clutch and a pair of diamond earrings and a cuff.
In March the same year she wore a very similar look, a stunning green lace gown with a pretty belt detail with a bow.
On both occasions her hair was left down, shiny and blow dried.
A body language expert recently analysed Meghan Markle’s body language at a performance of Hamilton.
The couple attended a special gala performance of the award-winning musical to raise money for Harry’s aids charity Sentebale.
Who is Meghan Markle? Quick profile
Meghan Markle was born Rachel Meghan Markle, on August 4, 1981 to parents Doria Ragland and father Thomas Markle.
Her father was previously married to Roslyn Loveless and Meghan has two elder half sibling – sister Samantha Markle and brother Thomas Markle Junior.
Meghan’s first television appearance in the USA was in an episode of the medical drama General Hospital in 2002.
She later moved on to roles in CSI, Without a Trace and Castle along with bit parts in Hollywood films including Get Him to the Greek, Remember Me and Horrible Bosses.
Meghan was also a “briefcase girl” on Deal or No Deal – but her most famous role was as Rachel Zane in legal drama Suits, which launched in 2011.
She was written out in the finale of the seventh series when her character got married, which aired in April 2018 – just before she got married herself.
Charity and humanitarian work
Meghan Markle’s career in television has gone hand-in-hand with her support for causes close to her heart.
She wrote about the stigma around menstrual health in an article for Time magazine and was a Global Ambassador for World Vision Canada – with whom she travelled to Rwanda for the charity’s Clean Water Campaign.
And her commitment to gender equality has seen her work with the United Nations – receiving a standing ovation in 2015 for her speech to mark International Women’s Day.
In September 2011, she wed film producer Trevor Engelson, who she began dating in 2004.
But the pair divorced two years later in August 2013, citing irreconcilable difference.
She was in a relationship with celebrity chef Cory Vitiello for almost two years, before they broke it off in 2016 but the two remain good friends.
And in June 2016, she met Prince Harry on a blind date set up by a mutual friend.
Their relationship began in October that year and just over one year later, on November 27, 2017, the pair announced their engagement.
They married on May 19, 2018 at St George’s Chapel in Windsor Castle.
Some have claimed Meghan Markle is the first mixed-race member of the Royal Family.
Historians are still arguing about Queen Charlotte, the wife of King George III.
But Meghan will be the first royal to openly embrace a mixed-race heritage.
She has written about the difficulties of being a biracial actress in Hollywood as she claims she is not black enough for some roles and not white enough for others.