The Ritz in Station Road will host its last party next year, although the adjacent R Inn restaurant and R Inn hotel will remain open.
Owner Kris Malde said no jobs will be lost as a result of the closure - and that plans are already in the pipeline for a new venture to open there.
He said: “It is with great sadness that I have to announce that the Ritz venue will be closing in 2021.
“This has been a very hard decision to make.
“Rather than bore everyone with the reasons for the closure of the Ritz, it is safe to say that we will not be putting any full-time staff out of work.
“Contrary to the good old Desborough rumour mill, I am not selling the Ritz nor building houses or flats on the land.
“Plans are being made and meetings are taking place for a new venture to operate from the Ritz in 2021.
“We are considering a number of options for the site but at the moment, I am unable to confirm anything definitive.”
However, Mr Malde said two of the alternatives being considered are childcare provision and elderly care provision.
The Ritz started life as Oddfellow’s Hall in 1888 and took on the Ritz name in 1938.
In about 1960 it became the Ritz Ballroom and was bought at a rock-bottom price by Mr Malde in 2010, who spent a year refurbishing it.
One of their first events was celebrating Desborough shoemaker Cheaney’s 125th anniversary in 2011.
In 2012 the world-famous Ritz Hotel in London ordered them to stop using the Ritz name.
In recent years Mr Malde has opened a number of ventures alongside the Ritz venue and the adjacent hotel featured on Channel 4’s Four in a Bed TV show.
Mr Malde said the hotel and restaurant are thriving and that his team will continue to put the community first after 2021.
He said: “My team and I would like to thank you [visitors] for your past, present and continued custom and we hope that you will make the most of our functions, events and Christmas parties this year and next, and be part of the Ritz history.
“2021 will be upon us sooner than you think.”
Messages of support have been left on the Friends of The Ritz Facebook group.
Mel Thorp said: “Very sad news. Yourself and your team were wonderful from start to finish for my wedding.”
Natasha Goodman said: “I’m absolutely gutted. You’ve turned the Ritz into something I don’t think anyone else ever could.”
The Ritz’s final event will be their annual New Year’s Eve dinner and dance on December 31, 2020.