Carole Middleton has a big smile on her face as she chats to Seb Coe in the Royal Box at Wimbledon, while enjoying a day out with her husband Michael

The Princess of Wales’ parents appeared to be in high spirits on the fourth day of Wimbledon, their second public appearance since their daughter was diagnosed with cancer.

Carole and Michael Middleton watched the action from the Royal Box with big smiles on Thursday.

The pair also appeared very focused as they played the second-round match between Serbia’s Novak Djokovic and Britain’s Jacob Fearnley.

Both laughed as they chatted with other attendees, including Sebastian Coe, the president of the International Association of Athletics Federations.

The radiant bride and groom looked their best as they arrived side by side for the prestigious event in London.

The Princess of Wales’ parents appeared to be in high spirits on the fourth day of Wimbledon – their second public appearance since their daughter’s cancer diagnosis

Carole, 69, wore a colourful floral print dress, paired with a cream jacket, while her husband, 75, opted for a navy suit and yellow tie.

The couple also brought sunglasses for the sunny day, with Carole wearing trendy retro glasses.

It follows their joyous appearance at Royal Ascot last month, where they were joined by members of the royal family, including their son-in-law Prince William, at the extravagant event.

The Middletons’ outings come after their daughter Kate, 42, who has undergone chemotherapy for an unknown form of cancer since February, made a spectacular return to public life last month during Trooping the Colour.

Carole is said to have supported her daughter at home in Windsor during her cancer treatment.

Michael and Carole’s last public appearance before Royal Ascot was at Kate’s annual Royal Carols: Together at Christmas at Westminster Abbey in London in December. Three months later, Kate announced her cancer diagnosis to the world.

But the royal parents recently returned to the spotlight at the summer social gathering after spending months away from their daughter.

They made a glamorous and cheerful appearance at Royal Ascot last month, where they attended the famous racing event alongside members of the royal family.

Both also laughed as they chatted with other attendees, including Sebastian Coe (left, talking to Carole), the president of the International Association of Athletics Federations

Dressed in all their finery, the radiant couple looked in good spirits as they arrived side by side for the prestigious event in London. Carole pictured chatting with Sir Sebastian Coe

Sebastian Coe and Carole Middleton pictured together during the fourth day of Wimbledon

Carole seemed to enjoy a chat with Sir Sebastian Coe, the president of the International Association of Athletics Federations

Carole and Michael Middleton had the biggest smiles on their faces as they watched the action from the Royal Box on Thursday night

Carole, Michael and other attendees laughed as they enjoyed the action on the fourth day of Wimbledon

Carole and her husband appeared to be in good spirits as they watched tennis from the Royal Box

Carole, 69, wore a colourful floral print dress, completed with a cream jacket, while her husband, 75, opted for a navy suit and yellow tie.

Carole wore her chestnut locks loose and styled herself, opting for a simple yet elegant makeup look

Kate Middleton’s mother also carried a woven handbag, creating the perfect summer ensemble

The Princess of Wales’ mother and father – Carole and Michael Middleton – attended the fourth day of Wimbledon, their second public appearance since their daughter was diagnosed with cancer

It is not known whether the Princess of Wales, who is patron of the All England Lawn Tennis and Croquet Club, will be attending this year’s tournament. Carole pictured at today’s event

However, other famous faces also appeared in the Royal Box during this year’s two-week event, including the Duchess of Gloucester, former Prime Minister Theresa May and star athlete Maria Sharapova.

Elsewhere, CEOs and entrepreneurs enjoyed the sport from the coveted seats yesterday.

Wimbledon is set to host the Battle of the Brits as Katie Boulter and Harriet Dart face off this afternoon.

Dressed in all their finery, the radiant couple looked in good spirits as they arrived side by side for the prestigious event in London

For today’s outing, mother of three Carole was the picture of elegance in a floral white, green and pink dress

Ready for the cooler British weather, she teamed the stunning dress with a white jacket with structured shoulders

The two British stars will test each other in front of a packed house on Court One during the women’s match.

In the men’s event, Jack Draper and Cameron Norrie will battle it out for a spot in the third round.

And for Andy Murray it will be an emotional match: he and his brother Jamie will play a doubles match on Centre Court. According to the veteran, this will be his last Wimbledon.

This is the first time the two brothers will play together at a Grand Slam, with young Jacob Fearnley taking on Serbian Novak Djokovic.