JTA Travel Group confirmed her passing in a special tribute shared with trade media on Monday (10 November), which described Court as "a great friend" and a "valued colleague" who leaves behind a "legacy of friendship and genuine care".
It hailed her "kindness, humour and unwavering passion for the people and places that make travel such a special business to be part of".
Court spent more than seven years at JTA Travel Group after roles with brands such as USAirtours, Destinology, Freedom Travel Group and Gold Medal in a career that spanned five decades.
JTA Travel Group said: "It is with great sadness that we share the news of the passing of our dear colleague and friend, Diane Court.
"Diane was much more than a respected professional within the travel industry, she was a warm, generous, and inspiring presence to everyone who had the privilege of working alongside her.
"Those who knew Diane will remember her for her integrity, her energy, her glamour, her infectious smile, and her ability to bring light to even the busiest of days. She was a true friend to so many of us, someone who always had time to listen, to support, and to celebrate the successes of others."
'We've lost a great friend'
The JTA statement added: "Her loss will be deeply felt across the industry, but her legacy of friendship, professionalism, and genuine care, will live on through the many people and partnerships she helped shape.
"From all of our team, we have not just lost a valued colleague, but a great friend. Diane was a constant source of encouragement and laughter, and we will always be grateful for the times we shared, both professionally and personally. She will be greatly missed, but never forgotten."
Kuoni head of trade partnerships Sarah Weetman said: "I met Diane when I first joined the travel industry more than 20 years ago. She was so experienced even at that point and was always smiling.
"When I was at an event in those early days she would always look out for me. I didn't know anybody at that stage. She was a genuine person who would always ask if you were ok. She was so supportive. I'm really shocked."
'Effortless style and grace'
Bob Lines, chair of Elite Travel Group, said: "When it does come to her funeral she will have one of the biggest turnouts anybody in travel has ever had. Everybody loved her. She knew everybody. Everybody who knew her was touched by her. I knew her for almost 40 years."
Not in the Guidebooks sales director Debbie Sowden knew Court for more than 25 years. "In all that time, she was one of the most genuine, warm and beautiful souls in our industry," she said.
"I have so many memories from conferences, events, late-night catch ups and laughs over the years. Her smile lit up every room she walked into, as did her amazing outfits ≠ always so glamorous.
"She had this effortless style and grace about her and a kindness that made everyone feel seen and valued. The travel world and all of us lucky enough to have known her have lost someone truly special."
Ian Gilder, Adore Holidays and Cruises managing director, said: "When I left Jetline, Diane came to my house in Bishop's Stortford to talk about Freedom Travel Group.
"We had the cleanest cream carpets that you will ever see and she left boot polish on them. She was mortified when I told her. That was 15, 16 years ago."
Gilder said Court "always had time for you". "She was just a very nice person," he continued. "You could never miss her at events. She was so tall and elegant. She had an aura about her. She was a lovely lady and is a huge loss to travel."
Court is survived by her husband Andrew and daughter Lisa.
