Carole Middleton is all smiles while chatting to Seb Coe in the Royal Box at Wimbledon as she enjoys a day out with husband Michael

The Princess of Wales' parents looked to be in high spirits on the fourth day of Wimbledon - in their second public appearance since their daughter's cancer diagnosis.

Carole and Michael Middleton were all smiles as they enjoyed watching the action from the Royal Box on Thursday.  

The couple also appeared very focused as they took in the second round match between Serbia's Novak Djokovic and Britain's Jacob Fearnley.

Both also laughed as they chatted with other attendees, including Sebastian Coe, the President of the International Association of Athletics Federations, who was seen sharing a giggle with an animated Carole. 

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

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

Carole, 69, donned a colourful floral print dress, topped with a cream blazer, while her husband, 75, opted for a deep blue suit and yellow tie. 

The pair also brought shades for the sunny day - with Carole sporting trendy retro style glasses. 

It follows their cheerful appearance at Royal Ascot last month, when they joined members of the Royal Family, including their son-in-law Prince William, at the lavish occasion.

Walking besides her husband, Michael, Carole had recreated her daughter's ensemble from the same event in 2019.

Her £350 light blue floral chiffon dress from Self Portrait echoed Kate's £1,275 blue lace creation by Elie Saab, and not to mention the floral-focused fascinators and matching shoes.

In 2019, Kate turned heads as she arrived at Royal Ascot in a flowing powder blue ensemble by Elie Saab - the first time she wore the Lebanese label that boasts a host of A-list fans.

The Middletons' outings come after their daughter Kate - who has been receiving chemotherapy for an undisclosed form of cancer since February - made a spectacular return to public life during Trooping the Colour last month. 

The Princess of Wales had made a triumphant appearance, joining the Royal Family to celebrate the King's official birthday.

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

Dressed in all their finery, the beaming 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 sat together while attending day four of Wimbledon

Carole appeared to enjoy a chat with Sir Sebastian Coe, who is the President of the International Association of Athletics Federations

Kate beamed and waved as she and her three children, Prince George, Princess Charlotte and Prince Louis, were cheered by crowds in The Mall after leaving Buckingham Palace in a carriage procession for the Trooping the Colour ceremony.

After spending much of the year coming to terms with the diagnosis and receiving ongoing chemotherapy, the future queen looked relaxed as she travelled along one of London's most famous thoroughfares with her family in the glass state coach.

Kate was surrounded by other members of the family - with her husband Prince William, Colonel of the Welsh Guards, on horseback, along with Princess Anne, Colonel of the Blues and Royals, and Prince Edward, Colonel of the Scots Guards.

Carole has reportedly been supporting her daughter through her cancer treatment at her home in Windsor.

Carole and Michael Middleton were all smiles as they enjoyed watching the action from the Royal Box on Thursday

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

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

Carole, 69, donned a colourful floral print dress, topped with a cream blazer, while her husband, 75, opted for a deep blue suit and yellow tie

Carole wore her chestnut tresses down, and styled, opting for a simple yet elegant make-up look

The mother of Kate Middleton also carried onto a woven handbag, making for the perfect summer ensemble

The Princess of Wales' mother and father - Carole and Michael Middleton - have attended the fourth day of Wimbledon, in their second public appearance since their daughter's cancer diagnosis

It isn't known whether the Princess of Wales, who is the patron of the All England Lawn Tennis and Croquet Club, will attend this year's tournament. Carole pictured at today's event

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 to the world her cancer diagnosis.

But the royal's parents have returned to the spotlight recently for the summer social scene after spending months at their daughter's side. 

Both Kate and King Charles III have thanked the public for their support after going public with their illnesses, with Kate saying she had been 'blown away' by the 'kind messages' that had made a 'world of difference to William and me and has helped us both through some of the harder times'. 

Kate was initially admitted to hospital for abdominal surgery on January 16 and at the time her condition was thought to be non-cancerous, but cancer was found following the successful operation.

Charles was admitted to hospital just days after Kate, also for a procedure deemed unrelated to cancer.

Dressed in all their finery, the beaming 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 frock with a white blazer, featuring structured shoulders

In February, Buckingham Palace confirmed that he had been diagnosed with a form of cancer, which is not prostate cancer, that was discovered while the King was being treated at the private London Clinic for an enlarged prostate.

Charles initially postponed public-facing duties but resumed at the end of April, speaking of his 'shock' at being diagnosed with cancer as he met patients during a visit to University College Hospital Macmillan Cancer Centre in central London.

Elsewhere at Wimbledon this month, other recognisable faces have appeared in the Royal Box during the two-week event this year, including the Duchess of Gloucester, former Prime Minister Theresa May, and star athlete Maria Sharapova.

Meanwhile, CEOs and entrepreneurs enjoyed taking in the sport from the coveted seats yesterday.

And on the court today, British number one Katie Boulter has lost to Harriet Dart after a nail-biting tie breaker.

It was the Battle of the Brits at Wimbledon on Thursday as wildcard Jacob Fearnley broke Novak Djokovic and tennis legend Andy Murray steps onto the double's court alongside his brother Jamie to begin his farewell to SW19.

The Middletons' outings come after their daughter Kate - who has been receiving chemotherapy for an undisclosed form of cancer since February - made a spectacular return to public life during Trooping the Colour last month

It follows their cheerful appearance at Royal Ascot last month, when they joined members of the Royal Family , including their son-in-law Prince William , at the lavish occasion

Walking besides her husband, Michael , Carole had recreated her daughter's ensemble from the same event in 2019

Both Kate and King Charles III have thanked the public for their support after going public with their illnesses

Fearnley, who was ranked outside the world's top 500 ahead of the tournament, fought his back in his match against seven-time world champion Djokovic.

The 22-year-old Scot only qualified for the Nottingham Open at the start of last month, admitted that 'it was getting in [his] head a little bit' that he was going to have take on the Serbian legend. 

This afternoon, more British athletes will face each other on court, with 22-year-old Jack Draper will take on South African born Brit Cameron Norrie to battle it out to get a place in the third round. 

 Both 27 years old, Boulter and Dart have spent over two decades in one another's orbit, both growing up so emmeshed in the tennis world that their mothers - Sue Boulter and Susie Dart - had even met as players during their own early careers.  

The pair are friends - and Boulter has spoken about how 'awful' it can be to play her Billie Jean King Cup team-mate.