Gregg Sulkin says Meghan, Duchess of Sussex, is "one of the most sincere and genuine people" he knows.

The 26-year-old actor worked with the former actress - who was known as Meghan Markle before tying the knot with Prince Harry in May last year - in the 2015 film 'Anti-Social', and has said she was just as much of a "princess" before she met Prince Harry as she is now that she's married to him.

Gregg said: "Everybody does know her as a princess, but in real life, she genuinely is also like a princess. She is one of the classiest, the nicest, one of the most sincere and genuine people I've ever met."

The British actor also praised the royal - who is currently expecting her first child with Harry - for how well she's handled the negative criticism that has surrounded her since her relationship with the flame-haired prince went public.

Gregg Sulkin starred in the 2015 film 'Anti-Social' with Markle. Photo / Getty Images
Gregg Sulkin starred in the 2015 film 'Anti-Social' with Markle. Photo / Getty Images

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Speaking during an appearance on 'Fair Game with Kristine Leahy', he added: "She's a superstar. She was a superstar. To me, I'm so proud the fact that she's part of my country's history in all honesty, aside from obviously having a personal relationship with her. I just think the way she's handle it – obviously the press of … you know, it hasn't been easy for her. And she's stuck to her guns, which is, you know, 'when they go low, we go high' sort of mentality and I think she's done that. I think she's been a class act."

Gregg isn't the only Hollywood pal of Meghan's to defend her from online trolls either, as George Clooney recently called treatment of the Duchess from haters "unjust".

He said: "I think it's a little unfair at times when – I've seen it when the press can turn on you for sort of ridiculous reasons and for almost nothing, and it seemed to me to be a little unjust since [Meghan] hadn't done anything except just happen to live her life."