Matthew McConaughey praised for unexpected gesture to Kate Middleton when he saw her at Wimbledon

Matthew McConaughey has been hailed a 'southern gentleman' for the behaviour he directed towards the Princess of Wales in Wimbledon's Royal Box.

The actor sat shoulder-to-shoulder with high-profile members of society for the Men's Singles match on Sunday (13 July), where he witnessed Italy's Jannik Sinner steal victory from reigning champion Carlos Alcaraz of Spain.

Kate, who was appointed as patron of the All England Lawn Tennis and Croquet Club in 2016 by Queen Elizabeth II, was also in attendance with her husband, Prince William. The Wales' were joined by their two eldest children - Prince George, 11, and ten-year-old Princess Charlotte.

In clips of the family descending the stairs to the box, a number of huge-name stars can be seen smiling in the background - including actors Paul Mescal and Andrew Scott, businessman Richard Branson, London Mayor Sadiq Khan and Vogue's Anna Wintour.

A number of stars were seated in the royal box (Visionhaus via Getty Images)

As Kate and William began taking their seats after shaking hands with a number of officials and fellow attendees, crowds in the stands gave the royals a standing ovation.

The tournament marks the second that Kate has attended since she announced in March of last year that she'd been diagnosed with cancer.

While other members of the royal box stayed seated for the gesture, 55-year-old Oscar winner McConaughey stood proudly as he clapped for the Princess.

And as such, he has garnered mass praise from a number of viewers watching from home, one of whom wrote on social media: "Matthew McConaughey standing to applaud the Prince & Princess of Wales.

"What a lovely southern gentleman."

Another penned on X: "Real Class."

"[Kate’s] looking lovely, as she did yesterday as well. And the applause for her is well deserved," a third continued. "People genuinely wish her well, after what she's been through."

The mother-of-three announced back in January that her cancer is now in remission, and earlier this month, she appeared at Colchester Hospital’s wellbeing garden, where she made another emotional admission.

The actor stood clapping as Kate approached (Tim Clayton/Getty Images)

Kate received a standing ovation (Julian Finney/Getty Images)

"You put on a sort of brave face, stoicism through treatment," she told attendees. "Treatment's done, then it's like, 'I can crack on, get back to normal,' but actually, the phase afterwards is really, really difficult.

"You're not necessarily under the clinical team any longer, but you're not able to function normally at home as you perhaps once used to.

"And actually, someone to help talk you through that, show you and guide you through that sort of phase that comes after treatment, I think is really valuable."